From b497e6d54d793f4143fae055feb3f29a7b081325 Mon Sep 17 00:00:00 2001
From: Frederik Kratzert <f.kratzert@gmail.com>
Date: Wed, 15 Oct 2025 08:26:46 +0000
Subject: [PATCH 1/3] get_data now returns time indexed dataframes

---
 examples/test_australia_fetcher.py   | 4 ++--
 examples/test_canada_fetcher.py      | 4 ++--
 examples/test_chile_fetcher.py       | 4 ++--
 examples/test_france_fetcher.py      | 6 +++---
 examples/test_japan_fetcher.py       | 4 ++--
 examples/test_poland_fetcher.py      | 4 ++--
 examples/test_slovenia_fetcher.py    | 4 ++--
 examples/test_southafrica_fetcher.py | 4 ++--
 examples/test_uk_fetcher.py          | 2 +-
 examples/test_uk_nrfa_fetcher.py     | 4 ++--
 examples/test_usa_fetcher.py         | 4 ++--
 rivretrieve/australia.py             | 2 +-
 rivretrieve/base.py                  | 6 ++++--
 rivretrieve/canada.py                | 2 +-
 rivretrieve/chile.py                 | 4 ++--
 rivretrieve/france.py                | 2 +-
 rivretrieve/japan.py                 | 6 +++---
 rivretrieve/poland.py                | 2 +-
 rivretrieve/slovenia.py              | 4 ++--
 rivretrieve/southafrica.py           | 2 +-
 rivretrieve/uk.py                    | 4 ++--
 rivretrieve/uk_nrfa.py               | 4 ++--
 rivretrieve/usa.py                   | 2 +-
 tests/test_australia.py              | 2 +-
 tests/test_canada.py                 | 4 ++--
 tests/test_chile.py                  | 2 +-
 tests/test_france.py                 | 2 +-
 tests/test_japan.py                  | 4 ++--
 tests/test_poland.py                 | 8 ++++----
 tests/test_slovenia.py               | 8 ++++----
 tests/test_uk.py                     | 4 ++--
 tests/test_uk_nrfa.py                | 4 ++--
 tests/test_usa.py                    | 4 ++--
 33 files changed, 64 insertions(+), 62 deletions(-)

diff --git a/examples/test_australia_fetcher.py b/examples/test_australia_fetcher.py
index 122166d..2f5b424 100644
--- a/examples/test_australia_fetcher.py
+++ b/examples/test_australia_fetcher.py
@@ -23,9 +23,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker="o",
diff --git a/examples/test_canada_fetcher.py b/examples/test_canada_fetcher.py
index 29abfc4..7e6b7b6 100644
--- a/examples/test_canada_fetcher.py
+++ b/examples/test_canada_fetcher.py
@@ -20,9 +20,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker=".",
diff --git a/examples/test_chile_fetcher.py b/examples/test_chile_fetcher.py
index 4961d2a..9552375 100644
--- a/examples/test_chile_fetcher.py
+++ b/examples/test_chile_fetcher.py
@@ -20,9 +20,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker=".",
diff --git a/examples/test_france_fetcher.py b/examples/test_france_fetcher.py
index e5fbb5d..da1983b 100644
--- a/examples/test_france_fetcher.py
+++ b/examples/test_france_fetcher.py
@@ -20,15 +20,15 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker=".",
             linestyle="-",
         )
-        plt.xlim(data[constants.TIME_INDEX].min(), data[constants.TIME_INDEX].max())
+        plt.xlim(data.index.min(), data.index.max())
     else:
         print(f"No data found for {gauge_id}")
 
diff --git a/examples/test_japan_fetcher.py b/examples/test_japan_fetcher.py
index a9c573b..ca565cc 100644
--- a/examples/test_japan_fetcher.py
+++ b/examples/test_japan_fetcher.py
@@ -22,9 +22,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker="o",
diff --git a/examples/test_poland_fetcher.py b/examples/test_poland_fetcher.py
index 6df1e6b..782c726 100644
--- a/examples/test_poland_fetcher.py
+++ b/examples/test_poland_fetcher.py
@@ -29,9 +29,9 @@
         if not data.empty:
             print(f"Data for {gauge_id}:")
             print(data.head())
-            print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+            print(f"Time series from {data.index.min()} to {data.index.max()}")
             plt.plot(
-                data[constants.TIME_INDEX],
+                data.index,
                 data[variable],
                 label=gauge_id,
                 marker=".",
diff --git a/examples/test_slovenia_fetcher.py b/examples/test_slovenia_fetcher.py
index 65ff03c..c3a822c 100644
--- a/examples/test_slovenia_fetcher.py
+++ b/examples/test_slovenia_fetcher.py
@@ -20,9 +20,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker="o",
diff --git a/examples/test_southafrica_fetcher.py b/examples/test_southafrica_fetcher.py
index 23cb818..3a98f40 100644
--- a/examples/test_southafrica_fetcher.py
+++ b/examples/test_southafrica_fetcher.py
@@ -20,9 +20,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker=".",
diff --git a/examples/test_uk_fetcher.py b/examples/test_uk_fetcher.py
index 2fef0a1..19031eb 100644
--- a/examples/test_uk_fetcher.py
+++ b/examples/test_uk_fetcher.py
@@ -19,7 +19,7 @@
         print(f"Data for {gauge_id}:")
         print(data.head())
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id.split("/")[-1],
         )
diff --git a/examples/test_uk_nrfa_fetcher.py b/examples/test_uk_nrfa_fetcher.py
index 14d76c9..54c6894 100644
--- a/examples/test_uk_nrfa_fetcher.py
+++ b/examples/test_uk_nrfa_fetcher.py
@@ -31,9 +31,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker=".",
diff --git a/examples/test_usa_fetcher.py b/examples/test_usa_fetcher.py
index 4d12573..da6ba17 100644
--- a/examples/test_usa_fetcher.py
+++ b/examples/test_usa_fetcher.py
@@ -23,9 +23,9 @@
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
-        print(f"Time series from {data[constants.TIME_INDEX].min()} to {data[constants.TIME_INDEX].max()}")
+        print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
-            data[constants.TIME_INDEX],
+            data.index,
             data[constants.DISCHARGE],
             label=gauge_id,
             marker="o",
diff --git a/rivretrieve/australia.py b/rivretrieve/australia.py
index 01525ab..4a1b445 100644
--- a/rivretrieve/australia.py
+++ b/rivretrieve/australia.py
@@ -148,7 +148,7 @@ def _parse_data(self, gauge_id: str, raw_data: Optional[str], variable: str) ->
             df["Value"] = pd.to_numeric(df["Value"], errors="coerce")
             df = df.rename(columns={"Value": variable})
             df[constants.TIME_INDEX] = pd.to_datetime(df[constants.TIME_INDEX])
-            return df[[constants.TIME_INDEX, variable]].dropna()
+            return df[[constants.TIME_INDEX, variable]].dropna().set_index(constants.TIME_INDEX)
         except Exception as e:
             logger.error(f"Error parsing CSV data for site {gauge_id}: {e}")
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
diff --git a/rivretrieve/base.py b/rivretrieve/base.py
index 7ea8010..fd6746c 100644
--- a/rivretrieve/base.py
+++ b/rivretrieve/base.py
@@ -25,12 +25,14 @@ def get_data(
 
         Args:
             gauge_id: The site-specific identifier for the gauge.
-            variable: The variable to fetch (e.g., 'stage' or 'discharge').
+            variable: The variable to fetch, should be one of the values from constants.py
+                (e.g., constants.DISCHARGE, constants.STAGE).
             start_date: Optional start date in 'YYYY-MM-DD' format.
             end_date: Optional end date in 'YYYY-MM-DD' format.
 
         Returns:
-            A pandas DataFrame with 'Date' and the variable column ('H' or 'Q').
+            A pandas DataFrame indexed by time (constants.TIME_INDEX) with a column
+            for the requested variable (e.g., constants.DISCHARGE).
         """
         pass
 
diff --git a/rivretrieve/canada.py b/rivretrieve/canada.py
index 9d788a5..589c414 100644
--- a/rivretrieve/canada.py
+++ b/rivretrieve/canada.py
@@ -186,7 +186,7 @@ def get_data(
                 df_long[[constants.TIME_INDEX, variable]]
                 .dropna()
                 .sort_values(by=constants.TIME_INDEX)
-                .reset_index(drop=True)
+                .set_index(constants.TIME_INDEX)
             )
 
         except Exception as e:
diff --git a/rivretrieve/chile.py b/rivretrieve/chile.py
index 930df5e..0ad25de 100644
--- a/rivretrieve/chile.py
+++ b/rivretrieve/chile.py
@@ -104,7 +104,7 @@ def _parse_data(
                 df[[constants.TIME_INDEX, variable]]
                 .dropna()
                 .sort_values(by=constants.TIME_INDEX)
-                .reset_index(drop=True)
+                .set_index(constants.TIME_INDEX)
             )
         except Exception as e:
             logger.error(f"Error parsing data for site {gauge_id}: {e}")
@@ -135,7 +135,7 @@ def get_data(
             # Filter by date range
             start_date_dt = pd.to_datetime(start_date)
             end_date_dt = pd.to_datetime(end_date)
-            df = df[(df[constants.TIME_INDEX] >= start_date_dt) & (df[constants.TIME_INDEX] <= end_date_dt)]
+            df = df[(df.index >= start_date_dt) & (df.index <= end_date_dt)]
             return df
         except Exception as e:
             logger.error(f"Failed to get data for site {gauge_id}, variable {variable}: {e}")
diff --git a/rivretrieve/france.py b/rivretrieve/france.py
index 96972b9..64791fa 100644
--- a/rivretrieve/france.py
+++ b/rivretrieve/france.py
@@ -107,7 +107,7 @@ def _parse_data(
                 df[[constants.TIME_INDEX, variable]]
                 .dropna()
                 .sort_values(by=constants.TIME_INDEX)
-                .reset_index(drop=True)
+                .set_index(constants.TIME_INDEX)
             )
         except Exception as e:
             logger.error(f"Error parsing JSON data for site {gauge_id}: {e}")
diff --git a/rivretrieve/japan.py b/rivretrieve/japan.py
index 8817dcb..eb818c2 100644
--- a/rivretrieve/japan.py
+++ b/rivretrieve/japan.py
@@ -141,9 +141,9 @@ def _parse_data(
 
         final_df = pd.concat(all_dfs, ignore_index=True)
         final_df = final_df.rename(columns={"Value": variable})
-        final_df = final_df.sort_values(by=constants.TIME_INDEX).reset_index(drop=True)
+        final_df = final_df.sort_values(by=constants.TIME_INDEX)
 
-        return final_df
+        return final_df.set_index(constants.TIME_INDEX)
 
     def get_data(
         self,
@@ -164,7 +164,7 @@ def get_data(
 
             start_date_dt = pd.to_datetime(start_date)
             end_date_dt = pd.to_datetime(end_date)
-            df = df[(df[constants.TIME_INDEX] >= start_date_dt) & (df[constants.TIME_INDEX] <= end_date_dt)]
+            df = df[(df.index >= start_date_dt) & (df.index <= end_date_dt)]
             return df
 
         except Exception as e:
diff --git a/rivretrieve/poland.py b/rivretrieve/poland.py
index 1f46116..f8619e8 100644
--- a/rivretrieve/poland.py
+++ b/rivretrieve/poland.py
@@ -209,7 +209,7 @@ def get_data(
 
             data_array = ds[variable].sel(gauge_id=gauge_id, time=slice(start_date, end_date))
             df = data_array.to_pandas().dropna().reset_index().rename(columns={variable: variable})
-            return df[[constants.TIME_INDEX, variable]]
+            return df.set_index(constants.TIME_INDEX)[[variable]]
 
         except KeyError:
             logger.info(f"No data found for gauge {gauge_id} in the selected date range.")
diff --git a/rivretrieve/slovenia.py b/rivretrieve/slovenia.py
index 72f8159..4fb0f44 100644
--- a/rivretrieve/slovenia.py
+++ b/rivretrieve/slovenia.py
@@ -85,7 +85,7 @@ def _parse_data(self, gauge_id: str, raw_data: Optional[str], variable: str) ->
                 df[[constants.TIME_INDEX, variable]]
                 .dropna()
                 .sort_values(by=constants.TIME_INDEX)
-                .reset_index(drop=True)
+                .set_index(constants.TIME_INDEX)
             )
 
         except Exception as e:
@@ -113,7 +113,7 @@ def get_data(
             # Filter by date range
             start_date_dt = pd.to_datetime(start_date)
             end_date_dt = pd.to_datetime(end_date)
-            df = df[(df[constants.TIME_INDEX] >= start_date_dt) & (df[constants.TIME_INDEX] <= end_date_dt)]
+            df = df[(df.index >= start_date_dt) & (df.index <= end_date_dt)]
             return df
         except Exception as e:
             logger.error(f"Failed to get data for site {gauge_id}, variable {variable}: {e}")
diff --git a/rivretrieve/southafrica.py b/rivretrieve/southafrica.py
index 6d403b6..450e8ac 100644
--- a/rivretrieve/southafrica.py
+++ b/rivretrieve/southafrica.py
@@ -155,7 +155,7 @@ def _parse_data(
                 daily_df = full_df[[constants.TIME_INDEX, "D_AVG_FR"]].rename(columns={"D_AVG_FR": "Value"})
 
             daily_df = daily_df.rename(columns={"Value": variable})
-            return daily_df.dropna().sort_values(by=constants.TIME_INDEX).reset_index(drop=True)
+            return daily_df.dropna().sort_values(by=constants.TIME_INDEX).set_index(constants.TIME_INDEX)
 
         except Exception as e:
             logger.error(f"Error parsing data for site {gauge_id}: {e}")
diff --git a/rivretrieve/uk.py b/rivretrieve/uk.py
index 3754275..237315d 100644
--- a/rivretrieve/uk.py
+++ b/rivretrieve/uk.py
@@ -126,7 +126,7 @@ def _parse_data(self, gauge_id: str, raw_data: List[Dict[str, Any]], variable: s
             complete_ts = pd.DataFrame(date_range, columns=[constants.TIME_INDEX])
             df_daily = pd.merge(complete_ts, df_daily, on=constants.TIME_INDEX, how="left")
 
-        return df_daily
+        return df_daily.set_index(constants.TIME_INDEX)
 
     def get_data(
         self,
@@ -148,7 +148,7 @@ def get_data(
             # Filter by exact start and end date after processing
             start_date_dt = pd.to_datetime(start_date)
             end_date_dt = pd.to_datetime(end_date)
-            df = df[(df[constants.TIME_INDEX] >= start_date_dt) & (df[constants.TIME_INDEX] <= end_date_dt)]
+            df = df[(df.index >= start_date_dt) & (df.index <= end_date_dt)]
             return df
 
         except Exception as e:
diff --git a/rivretrieve/uk_nrfa.py b/rivretrieve/uk_nrfa.py
index 07186c5..18747a4 100644
--- a/rivretrieve/uk_nrfa.py
+++ b/rivretrieve/uk_nrfa.py
@@ -102,7 +102,7 @@ def _parse_data(self, gauge_id: str, raw_data: Optional[Dict[str, Any]], variabl
             df[constants.TIME_INDEX] = pd.to_datetime(df["time"], format="ISO8601").dt.date
             df[constants.TIME_INDEX] = pd.to_datetime(df[constants.TIME_INDEX])
             df[variable] = pd.to_numeric(df[variable], errors="coerce")
-            return df[[constants.TIME_INDEX, variable]].dropna().reset_index(drop=True)
+            return df[[constants.TIME_INDEX, variable]].dropna().set_index(constants.TIME_INDEX)
         except Exception as e:
             logger.error(f"Error parsing NRFA data for {gauge_id}: {e}")
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
@@ -128,7 +128,7 @@ def get_data(
             # Filter by date range
             start_date_dt = pd.to_datetime(start_date)
             end_date_dt = pd.to_datetime(end_date)
-            df = df[(df[constants.TIME_INDEX] >= start_date_dt) & (df[constants.TIME_INDEX] <= end_date_dt)]
+            df = df[(df.index >= start_date_dt) & (df.index <= end_date_dt)]
             return df
         except Exception as e:
             logger.error(f"Failed to get data for site {gauge_id}, variable {variable}: {e}")
diff --git a/rivretrieve/usa.py b/rivretrieve/usa.py
index c689fc1..0ded443 100644
--- a/rivretrieve/usa.py
+++ b/rivretrieve/usa.py
@@ -76,7 +76,7 @@ def _parse_data(self, gauge_id: str, raw_data: pd.DataFrame, variable: str) -> p
             mult = 0.0283168466
         df[variable] = pd.to_numeric(df[value_col], errors="coerce") * mult
 
-        return df[[constants.TIME_INDEX, variable]].dropna()
+        return df[[constants.TIME_INDEX, variable]].dropna().set_index(constants.TIME_INDEX)
 
     def get_data(
         self,
diff --git a/tests/test_australia.py b/tests/test_australia.py
index a81c9d6..9f63588 100644
--- a/tests/test_australia.py
+++ b/tests/test_australia.py
@@ -47,7 +47,7 @@ def bom_request_side_effect(params):
             constants.TIME_INDEX: pd.to_datetime(["2010-01-01", "2010-01-02", "2010-01-03"]),
             constants.DISCHARGE: [0.000, 3.710, 3.211],
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
         assert_frame_equal(result_df, expected_df)
         self.assertEqual(mock_make_bom_request.call_count, 2)
diff --git a/tests/test_canada.py b/tests/test_canada.py
index 6771741..85c2079 100644
--- a/tests/test_canada.py
+++ b/tests/test_canada.py
@@ -36,7 +36,7 @@ def test_get_data_discharge(self, mock_hydat_path, mock_download, mock_requests)
             ),
             constants.DISCHARGE: [1.1, 1.2, 1.3, 1.4, 1.5],
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
         assert_frame_equal(result_df, expected_df)
 
@@ -62,7 +62,7 @@ def test_get_data_stage(self, mock_hydat_path, mock_download, mock_requests):
             ),
             constants.STAGE: [10.1, 10.2, 10.3, 10.4, 10.5],
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
         assert_frame_equal(result_df, expected_df)
 
diff --git a/tests/test_chile.py b/tests/test_chile.py
index 0f35af0..cd86075 100644
--- a/tests/test_chile.py
+++ b/tests/test_chile.py
@@ -50,7 +50,7 @@ def get_side_effect(*args, **kwargs):
             constants.TIME_INDEX: pd.to_datetime(["2022-01-01", "2022-01-02", "2022-01-03"]),
             constants.DISCHARGE: [15.5, 16.0, 15.8],
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
         assert_frame_equal(result_df, expected_df)
         self.assertEqual(mock_get.call_count, 2)
diff --git a/tests/test_france.py b/tests/test_france.py
index 9d056d7..6d5701e 100644
--- a/tests/test_france.py
+++ b/tests/test_france.py
@@ -38,7 +38,7 @@ def test_get_data_discharge(self, mock_get):
             constants.TIME_INDEX: pd.to_datetime(["2023-01-01", "2023-01-02", "2023-01-03"]),
             constants.DISCHARGE: [15.0005, 16.0000, 15.5002],  # Divided by 1000
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
         assert_frame_equal(result_df, expected_df)
         mock_get.assert_called_once()
diff --git a/tests/test_japan.py b/tests/test_japan.py
index 7501af3..423c65b 100644
--- a/tests/test_japan.py
+++ b/tests/test_japan.py
@@ -40,9 +40,9 @@ def test_get_data_discharge(self, mock_get):
             constants.TIME_INDEX: expected_dates,
             constants.DISCHARGE: expected_values,
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-        assert_frame_equal(result_df.reset_index(drop=True), expected_df)
+        assert_frame_equal(result_df, expected_df)
         mock_get.assert_called_once()
         # Check that the params are correct
         mock_args, mock_kwargs = mock_get.call_args
diff --git a/tests/test_poland.py b/tests/test_poland.py
index 489f564..22e1681 100644
--- a/tests/test_poland.py
+++ b/tests/test_poland.py
@@ -46,9 +46,9 @@ def test_get_data_discharge(self, mock_create_cache):
                 constants.TIME_INDEX: expected_dates,
                 constants.DISCHARGE: expected_values,
             }
-            expected_df = pd.DataFrame(expected_data)
+            expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-            assert_frame_equal(result_df.reset_index(drop=True), expected_df)
+            assert_frame_equal(result_df, expected_df)
             mock_create_cache.assert_not_called()  # Cache should not be recreated
 
     @patch("rivretrieve.poland.PolandFetcher._create_cache")  # Mock cache creation
@@ -67,9 +67,9 @@ def test_get_data_stage(self, mock_create_cache):
                 constants.TIME_INDEX: expected_dates,
                 constants.STAGE: expected_values,
             }
-            expected_df = pd.DataFrame(expected_data)
+            expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-            assert_frame_equal(result_df.reset_index(drop=True), expected_df)
+            assert_frame_equal(result_df, expected_df)
             mock_create_cache.assert_not_called()
 
     @patch("rivretrieve.utils.requests_retry_session")
diff --git a/tests/test_slovenia.py b/tests/test_slovenia.py
index 1c66615..c254f29 100644
--- a/tests/test_slovenia.py
+++ b/tests/test_slovenia.py
@@ -45,9 +45,9 @@ def test_get_data_discharge(self, mock_requests_session):
             constants.TIME_INDEX: expected_dates,
             constants.DISCHARGE: expected_values,
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-        assert_frame_equal(result_df.reset_index(drop=True), expected_df)
+        assert_frame_equal(result_df, expected_df)
         mock_session.get.assert_called_once()
         mock_args, mock_kwargs = mock_session.get.call_args
         self.assertIn("p_postaja=1020", mock_args[0])
@@ -81,9 +81,9 @@ def test_get_data_stage(self, mock_requests_session):
             constants.TIME_INDEX: expected_dates,
             constants.STAGE: expected_values,
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-        assert_frame_equal(result_df.reset_index(drop=True), expected_df)
+        assert_frame_equal(result_df, expected_df)
 
 
 if __name__ == "__main__":
diff --git a/tests/test_uk.py b/tests/test_uk.py
index ec40aeb..ab980cd 100644
--- a/tests/test_uk.py
+++ b/tests/test_uk.py
@@ -61,9 +61,9 @@ def mock_get_side_effect(url, *args, **kwargs):
             constants.TIME_INDEX: expected_dates,
             constants.DISCHARGE: expected_values,
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-        assert_frame_equal(result_df.reset_index(drop=True), expected_df, check_dtype=False)
+        assert_frame_equal(result_df, expected_df, check_dtype=False)
         self.assertEqual(mock_session.get.call_count, 2)
 
 
diff --git a/tests/test_uk_nrfa.py b/tests/test_uk_nrfa.py
index 6e5aa08..56bc1d9 100644
--- a/tests/test_uk_nrfa.py
+++ b/tests/test_uk_nrfa.py
@@ -99,9 +99,9 @@ def test_get_data(self, variable, expected_data_type, sample_file, expected_valu
 
         expected_dates = pd.to_datetime(["2022-01-01", "2022-01-02", "2022-01-03", "2022-01-04", "2022-01-05"])
         expected_data = {constants.TIME_INDEX: expected_dates, variable: expected_values}
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-        assert_frame_equal(result_df.reset_index(drop=True), expected_df, check_dtype=False)
+        assert_frame_equal(result_df, expected_df, check_dtype=False)
         mock_session.get.assert_called_once()
         _, mock_kwargs = mock_session.get.call_args
         params = mock_kwargs["params"]
diff --git a/tests/test_usa.py b/tests/test_usa.py
index 09792d2..e7a16a2 100644
--- a/tests/test_usa.py
+++ b/tests/test_usa.py
@@ -51,9 +51,9 @@ def test_get_data_discharge(self, mock_get_dv):
             constants.TIME_INDEX: expected_dates,
             constants.DISCHARGE: expected_values,
         }
-        expected_df = pd.DataFrame(expected_data)
+        expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
-        assert_frame_equal(result_df.reset_index(drop=True), expected_df, check_dtype=False)
+        assert_frame_equal(result_df, expected_df, check_dtype=False)
         mock_get_dv.assert_called_once()
         mock_args, mock_kwargs = mock_get_dv.call_args
         self.assertEqual(mock_kwargs["sites"], gauge_id)

From 31db000981a06414caf4baf943810556d4ef69ab Mon Sep 17 00:00:00 2001
From: Frederik Kratzert <f.kratzert@gmail.com>
Date: Thu, 16 Oct 2025 20:30:45 +0000
Subject: [PATCH 2/3] Refactor: New names, Extended USA and South Africa, Fixed
 France

---
 examples/test_australia_fetcher.py   |   6 +--
 examples/test_canada_fetcher.py      |   6 +--
 examples/test_chile_fetcher.py       |   6 +--
 examples/test_france_fetcher.py      |   6 +--
 examples/test_japan_fetcher.py       |   6 +--
 examples/test_poland_fetcher.py      |   2 +-
 examples/test_slovenia_fetcher.py    |   6 +--
 examples/test_southafrica_fetcher.py |   8 ++--
 examples/test_uk_ea_fetcher.py       |   6 +--
 examples/test_uk_nrfa_fetcher.py     |   6 +--
 examples/test_usa_fetcher.py         |   6 +--
 rivretrieve/australia.py             |   6 +--
 rivretrieve/canada.py                |   6 +--
 rivretrieve/chile.py                 |  11 ++---
 rivretrieve/constants.py             |  50 ++++++++++++++++----
 rivretrieve/france.py                |  31 ++++++++-----
 rivretrieve/japan.py                 |   6 +--
 rivretrieve/poland.py                |  18 ++++----
 rivretrieve/slovenia.py              |   6 +--
 rivretrieve/southafrica.py           |  44 ++++++++++--------
 rivretrieve/uk_ea.py                 |  36 ++++++---------
 rivretrieve/uk_nrfa.py               |   6 +--
 rivretrieve/usa.py                   |  66 +++++++++++++++++++--------
 tests/test_australia.py              |   4 +-
 tests/test_canada.py                 |   8 ++--
 tests/test_chile.py                  |   4 +-
 tests/test_data/poland_test.zarr.zip | Bin 6447 -> 6955 bytes
 tests/test_france.py                 |   4 +-
 tests/test_japan.py                  |   4 +-
 tests/test_poland.py                 |  14 +++---
 tests/test_slovenia.py               |   8 ++--
 tests/test_southafrica.py            |   4 +-
 tests/test_uk_ea.py                  |   4 +-
 tests/test_uk_nrfa.py                |   4 +-
 tests/test_usa.py                    |   4 +-
 35 files changed, 238 insertions(+), 174 deletions(-)

diff --git a/examples/test_australia_fetcher.py b/examples/test_australia_fetcher.py
index 2f5b424..22631cc 100644
--- a/examples/test_australia_fetcher.py
+++ b/examples/test_australia_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "403213",
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 # Fetch a recent period for testing
 start_date = "2023-10-01"
 end_date = "2024-03-31"
@@ -26,7 +26,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker="o",
         )
@@ -34,7 +34,7 @@
         print(f"No data found for {gauge_id}")
 
 plt.xlabel(constants.TIME_INDEX)
-plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
 plt.title(f"Australia River Discharge ({gauge_ids[0]} - Full Time Series)")
 plt.legend()
 plt.grid(True)
diff --git a/examples/test_canada_fetcher.py b/examples/test_canada_fetcher.py
index 7e6b7b6..52f58f4 100644
--- a/examples/test_canada_fetcher.py
+++ b/examples/test_canada_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "01AD003",
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 
 plt.figure(figsize=(12, 6))
 
@@ -23,7 +23,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker=".",
             linestyle="-",
@@ -33,7 +33,7 @@
 
 if "data" in locals() and not data.empty:
     plt.xlabel(constants.TIME_INDEX)
-    plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+    plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
     plt.title(f"Canada River Discharge ({gauge_ids[0]} - Full Time Series)")
     plt.legend()
     plt.grid(True)
diff --git a/examples/test_chile_fetcher.py b/examples/test_chile_fetcher.py
index 9552375..37dd496 100644
--- a/examples/test_chile_fetcher.py
+++ b/examples/test_chile_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "01201005",
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 
 plt.figure(figsize=(12, 6))
 
@@ -23,7 +23,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker=".",
             linestyle="-",
@@ -33,7 +33,7 @@
 
 if "data" in locals() and not data.empty:
     plt.xlabel(constants.TIME_INDEX)
-    plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+    plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
     plt.title(f"Chile River Discharge ({gauge_ids[0]} - Full Time Series)")
     plt.legend()
     plt.grid(True)
diff --git a/examples/test_france_fetcher.py b/examples/test_france_fetcher.py
index da1983b..3cbebdc 100644
--- a/examples/test_france_fetcher.py
+++ b/examples/test_france_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "K027401001",
 ]
-variable = constants.DISCHARGE
+variable = constants.STAGE_DAILY_MAX
 
 plt.figure(figsize=(12, 6))
 
@@ -23,7 +23,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[variable],
             label=gauge_id,
             marker=".",
             linestyle="-",
@@ -34,7 +34,7 @@
 
 if not data.empty:
     plt.xlabel(constants.TIME_INDEX)
-    plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+    plt.ylabel(f"{variable} (m3/s)")
     plt.title(f"France River Discharge ({gauge_ids[0]} - Full Time Series)")
     plt.legend()
     plt.grid(True)
diff --git a/examples/test_japan_fetcher.py b/examples/test_japan_fetcher.py
index ca565cc..18ceed1 100644
--- a/examples/test_japan_fetcher.py
+++ b/examples/test_japan_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "301011281104010",
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 start_date = "2019-01-01"
 end_date = "2019-12-31"  # Fetching a few months to test
 
@@ -25,7 +25,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker="o",
         )
@@ -33,7 +33,7 @@
         print(f"No data found for {gauge_id}")
 
 plt.xlabel(constants.TIME_INDEX)
-plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
 plt.title("Japan River Discharge - Full Time Series")
 plt.legend()
 plt.grid(True)
diff --git a/examples/test_poland_fetcher.py b/examples/test_poland_fetcher.py
index 782c726..45058c8 100644
--- a/examples/test_poland_fetcher.py
+++ b/examples/test_poland_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "149180020",  # CHAŁUPKI on Odra
 ]
-variables = [constants.DISCHARGE, constants.STAGE, constants.WATER_TEMPERATURE]
+variables = [constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MEAN, constants.WATER_TEMPERATURE_DAILY_MEAN]
 # Fetch a period from Simon's example
 start_date = "1999-01-01"
 end_date = "2001-12-31"
diff --git a/examples/test_slovenia_fetcher.py b/examples/test_slovenia_fetcher.py
index c3a822c..a678bd8 100644
--- a/examples/test_slovenia_fetcher.py
+++ b/examples/test_slovenia_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "1020",  # Cmurek on Mura
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 
 plt.figure(figsize=(12, 6))
 
@@ -23,7 +23,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker="o",
         )
@@ -32,7 +32,7 @@
 
 if "data" in locals() and not data.empty:
     plt.xlabel(constants.TIME_INDEX)
-    plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+    plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
     plt.title(f"Slovenia River Discharge ({gauge_ids[0]} - Full Time Series)")
     plt.legend()
     plt.grid(True)
diff --git a/examples/test_southafrica_fetcher.py b/examples/test_southafrica_fetcher.py
index 3a98f40..0e427f5 100644
--- a/examples/test_southafrica_fetcher.py
+++ b/examples/test_southafrica_fetcher.py
@@ -9,21 +9,21 @@
 gauge_ids = [
     "X3H023",
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 
 plt.figure(figsize=(12, 6))
 
 fetcher = SouthAfricaFetcher()
 for gauge_id in gauge_ids:
     print(f"Fetching data for {gauge_id}...")
-    data = fetcher.get_data(gauge_id=gauge_id, variable=variable)
+    data = fetcher.get_data(gauge_id=gauge_id, variable=variable, start_date="2000-01-01", end_date="2005-12-31")
     if not data.empty:
         print(f"Data for {gauge_id}:")
         print(data.head())
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker=".",
             linestyle="-",
@@ -33,7 +33,7 @@
 
 if "data" in locals() and not data.empty:
     plt.xlabel(constants.TIME_INDEX)
-    plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+    plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
     plt.title(f"South Africa River Discharge ({gauge_ids[0]} - Full Time Series)")
     plt.legend()
     plt.grid(True)
diff --git a/examples/test_uk_ea_fetcher.py b/examples/test_uk_ea_fetcher.py
index e528193..3b0f92a 100644
--- a/examples/test_uk_ea_fetcher.py
+++ b/examples/test_uk_ea_fetcher.py
@@ -7,7 +7,7 @@
 ]
 start_date = "2024-01-01"
 end_date = "2024-01-31"
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 
 plt.figure(figsize=(12, 6))
 
@@ -20,14 +20,14 @@
         print(data.head())
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id.split("/")[-1],
         )
     else:
         print(f"No data found for {gauge_id}")
 
 plt.xlabel(constants.TIME_INDEX)
-plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
 plt.title("UK River Discharge - Full Time Series")
 plt.legend()
 plt.grid(True)
diff --git a/examples/test_uk_nrfa_fetcher.py b/examples/test_uk_nrfa_fetcher.py
index 54c6894..bcf0e0b 100644
--- a/examples/test_uk_nrfa_fetcher.py
+++ b/examples/test_uk_nrfa_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "1001",  # Sample gauge from issue #34
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 start_date = "2022-01-01"
 end_date = "2022-01-31"
 
@@ -34,7 +34,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker=".",
             linestyle="-",
@@ -44,7 +44,7 @@
 
 if "data" in locals() and not data.empty:
     plt.xlabel(constants.TIME_INDEX)
-    plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+    plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
     plt.title(f"UK NRFA River Discharge ({gauge_ids[0]} - {start_date} to {end_date})")
     plt.legend()
     plt.grid(True)
diff --git a/examples/test_usa_fetcher.py b/examples/test_usa_fetcher.py
index da6ba17..82cfa1d 100644
--- a/examples/test_usa_fetcher.py
+++ b/examples/test_usa_fetcher.py
@@ -9,7 +9,7 @@
 gauge_ids = [
     "07374000",
 ]
-variable = constants.DISCHARGE
+variable = constants.DISCHARGE_DAILY_MEAN
 # Fetch a recent period for testing
 start_date = "1950-01-01"
 end_date = None
@@ -26,7 +26,7 @@
         print(f"Time series from {data.index.min()} to {data.index.max()}")
         plt.plot(
             data.index,
-            data[constants.DISCHARGE],
+            data[constants.DISCHARGE_DAILY_MEAN],
             label=gauge_id,
             marker="o",
         )
@@ -34,7 +34,7 @@
         print(f"No data found for {gauge_id}")
 
 plt.xlabel(constants.TIME_INDEX)
-plt.ylabel(f"{constants.DISCHARGE} (m3/s)")
+plt.ylabel(f"{constants.DISCHARGE_DAILY_MEAN} (m3/s)")
 plt.title(f"USA River Discharge ({gauge_ids[0]} - 1950 to Present)")
 plt.legend()
 plt.grid(True)
diff --git a/rivretrieve/australia.py b/rivretrieve/australia.py
index 4a1b445..e6da17e 100644
--- a/rivretrieve/australia.py
+++ b/rivretrieve/australia.py
@@ -25,7 +25,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MEAN)
 
     def _make_bom_request(self, params: Dict[str, Any]) -> Any:
         """Helper function to make requests to the BoM API."""
@@ -51,10 +51,10 @@ def _make_bom_request(self, params: Dict[str, Any]) -> Any:
 
     def _get_timeseries_id(self, gauge_id: str, variable: str) -> Optional[str]:
         """Retrieves the timeseries ID for the given site and variable."""
-        if variable == constants.STAGE:
+        if variable == constants.STAGE_DAILY_MEAN:
             bom_variable = "Water Course Level"
             # ts_name = "H.Merged.DailyMean"
-        elif variable == constants.DISCHARGE:
+        elif variable == constants.DISCHARGE_DAILY_MEAN:
             bom_variable = "Water Course Discharge"
             # ts_name = "Q.Merged.DailyMean"
         else:
diff --git a/rivretrieve/canada.py b/rivretrieve/canada.py
index 589c414..16599d2 100644
--- a/rivretrieve/canada.py
+++ b/rivretrieve/canada.py
@@ -33,7 +33,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MEAN)
 
     def _find_latest_hydat_link(self) -> Optional[str]:
         s = utils.requests_retry_session()
@@ -130,8 +130,8 @@ def get_data(
             raise ValueError(f"Unsupported variable: {variable}")
 
         var_map = {
-            constants.DISCHARGE: {"table": "DLY_FLOWS", "prefix": "FLOW"},
-            constants.STAGE: {"table": "DLY_LEVELS", "prefix": "LEVEL"},
+            constants.DISCHARGE_DAILY_MEAN: {"table": "DLY_FLOWS", "prefix": "FLOW"},
+            constants.STAGE_DAILY_MEAN: {"table": "DLY_LEVELS", "prefix": "LEVEL"},
         }
 
         table = var_map[variable]["table"]
diff --git a/rivretrieve/chile.py b/rivretrieve/chile.py
index 0ad25de..4388fef 100644
--- a/rivretrieve/chile.py
+++ b/rivretrieve/chile.py
@@ -24,7 +24,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE,)
+        return (constants.DISCHARGE_DAILY_MEAN,)
 
     def _download_data(
         self,
@@ -33,9 +33,8 @@ def _download_data(
         start_date: str,
         end_date: str,
     ) -> Optional[pd.DataFrame]:
-        """Downloads the raw CSV data by first finding the download link."""
-        if variable != constants.DISCHARGE:
-            logger.warning(f"ChileFetcher only supports variable='{constants.DISCHARGE}'")
+        if variable != constants.DISCHARGE_DAILY_MEAN:
+            logger.warning(f"ChileFetcher only supports variable='{constants.DISCHARGE_DAILY_MEAN}'")
             return None
 
         # This long URL was extracted from the R code
@@ -118,8 +117,8 @@ def get_data(
         end_date: Optional[str] = None,
     ) -> pd.DataFrame:
         """Fetches and parses Chilean river gauge data."""
-        if variable != constants.DISCHARGE:
-            logger.warning(f"ChileFetcher only supports variable='{constants.DISCHARGE}'")
+        if variable != constants.DISCHARGE_DAILY_MEAN:
+            logger.warning(f"ChileFetcher only supports variable='{constants.DISCHARGE_DAILY_MEAN}'")
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
         start_date = utils.format_start_date(start_date)
diff --git a/rivretrieve/constants.py b/rivretrieve/constants.py
index 04384b4..f76dc2f 100644
--- a/rivretrieve/constants.py
+++ b/rivretrieve/constants.py
@@ -1,16 +1,10 @@
 """Module for global constants."""
 
-# Index
+# Index.
 GAUGE_ID = "gauge_id"
 TIME_INDEX = "time"
 
-# Data Variables
-DISCHARGE = "discharge"
-STAGE = "stage"
-WATER_TEMPERATURE = "water_temperature"
-CATCHMENT_PRECIPITATION = "catchment_precipitation"
-
-# Attributes
+# Attributes.
 ALTITUDE = "altitude"
 AREA = "area"
 COUNTRY = "country"
@@ -19,3 +13,43 @@
 RIVER = "river"
 SOURCE = "source"
 STATION_NAME = "station_name"
+
+# General list of variables.
+DISCHARGE = "discharge"
+STAGE = "stage"
+_WATER_TEMPERATURE = "water-temperature"
+_CATCHMENT_PRECIPITATION = "catchment-precipitation"
+
+# List of temporal resolutions.
+DAILY = "daily"
+_HOURLY = "60min"
+_15MIN = "15min"
+INSTANTANEOUS = "instantaneous"
+
+# List of temporal aggregrations.
+_MEAN = "mean"
+_MIN = "min"
+_MAX = "max"
+_SUM = "sum"
+
+# ------------------------------ Supported set of variables ----------------------------------------
+
+# Discharge.
+DISCHARGE_DAILY_MEAN = f"{DISCHARGE}_{DAILY}_{_MEAN}"
+DISCHARGE_DAILY_MAX = f"{DISCHARGE}_{DAILY}_{_MAX}"
+DISCHARGE_DAILY_MIN = f"{DISCHARGE}_{DAILY}_{_MIN}"
+DISCHARGE_15MIN = f"{DISCHARGE}_{_15MIN}"
+DISCHARGE_INSTANT = f"{DISCHARGE}_{INSTANTANEOUS}"
+
+# Stage.
+STAGE_DAILY_MEAN = f"{STAGE}_{DAILY}_{_MEAN}"
+STAGE_DAILY_MAX = f"{STAGE}_{DAILY}_{_MAX}"
+STAGE_DAILY_MIN = f"{STAGE}_{DAILY}_{_MIN}"
+STAGE_15MIN = f"{STAGE}_{_15MIN}"
+STAGE_INSTANT = f"{STAGE}_{INSTANTANEOUS}"
+
+# Water temperature.
+WATER_TEMPERATURE_DAILY_MEAN = f"{_WATER_TEMPERATURE}_{DAILY}_{_MEAN}"
+
+# Precipitation
+CATCHMENT_PRECIPITATION_DAILY_SUM = f"{_CATCHMENT_PRECIPITATION}_{DAILY}_{_SUM}"
diff --git a/rivretrieve/france.py b/rivretrieve/france.py
index 64791fa..dc0d47f 100644
--- a/rivretrieve/france.py
+++ b/rivretrieve/france.py
@@ -23,7 +23,21 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MAX)
+
+    def _get_variable_code(self, variable: str) -> str:
+        if variable == constants.DISCHARGE_DAILY_MEAN:
+            return "QmnJ"
+        elif variable == constants.STAGE_DAILY_MAX:
+            return "HIXnJ"
+        else:
+            logger.warning(f"Unsupported variable: {variable}")
+
+    def _conversion_factor(self, variable: str) -> float:
+        if variable.startswith(constants.DISCHARGE):
+            return 1000  # l/s for flow rates (divide by 1000 to convert to m3/s).
+        elif variable.startswith(constants.STAGE):
+            return 1000  # mm for water heights (divide by 1000 to convert to meters);
 
     def _download_data(
         self,
@@ -33,14 +47,8 @@ def _download_data(
         end_date: str,
     ) -> List[Dict[str, Any]]:
         """Downloads raw data from the Hubeau API."""
-        if variable == constants.DISCHARGE:
-            grandeur = "QmnJ"
-        elif variable == constants.STAGE:
-            grandeur = "HnJ"  # Assuming daily mean stage, though doc mentions HIXnJ
-            logger.warning("Using grandeur_hydro='HnJ' for stage, this might not be daily mean.")
-        else:
-            logger.warning(f"Unsupported variable: {variable}")
-            return []
+        grandeur = self._get_variable_code(variable)
+
         params = {
             "code_entite": gauge_id,
             "date_debut_obs": start_date,
@@ -92,7 +100,7 @@ def _parse_data(
             if df.empty:
                 return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
-            grandeur_code = "QmnJ" if variable == constants.DISCHARGE else "HnJ"
+            grandeur_code = self._get_variable_code(variable)
             df = df[df["grandeur_hydro_elab"] == grandeur_code]
 
             if df.empty or "date_obs_elab" not in df.columns or "resultat_obs_elab" not in df.columns:
@@ -100,8 +108,7 @@ def _parse_data(
                 return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
             df[constants.TIME_INDEX] = pd.to_datetime(df["date_obs_elab"]).dt.date
-            # Convert L/s to m3/s
-            df[variable] = pd.to_numeric(df["resultat_obs_elab"], errors="coerce") / 1000.0
+            df[variable] = pd.to_numeric(df["resultat_obs_elab"], errors="coerce") / self._conversion_factor(variable)
             df[constants.TIME_INDEX] = pd.to_datetime(df[constants.TIME_INDEX])
             return (
                 df[[constants.TIME_INDEX, variable]]
diff --git a/rivretrieve/japan.py b/rivretrieve/japan.py
index eb818c2..13fc1f9 100644
--- a/rivretrieve/japan.py
+++ b/rivretrieve/japan.py
@@ -27,12 +27,12 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MEAN)
 
     def _get_kind(self, variable: str) -> int:
-        if variable == constants.STAGE:
+        if variable == constants.STAGE_DAILY_MEAN:
             return 2
-        elif variable == constants.DISCHARGE:
+        elif variable == constants.DISCHARGE_DAILY_MEAN:
             return 6
         else:
             raise ValueError(f"Unsupported variable: {variable}")
diff --git a/rivretrieve/poland.py b/rivretrieve/poland.py
index f8619e8..7f08532 100644
--- a/rivretrieve/poland.py
+++ b/rivretrieve/poland.py
@@ -31,7 +31,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE, constants.WATER_TEMPERATURE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MEAN, constants.WATER_TEMPERATURE_DAILY_MEAN)
 
     def _get_metadata_headers(self):
         """Fetches and cleans metadata headers."""
@@ -109,9 +109,9 @@ def _parse_all_data(self, raw_data_list: List[pd.DataFrame]) -> pd.DataFrame:
             full_df = full_df.rename(
                 columns={
                     "Kod stacji": constants.GAUGE_ID,
-                    "Przepływ [m3/s]": constants.DISCHARGE,
-                    "Stan wody [cm]": constants.STAGE,
-                    "Temperatura wody [st. C]": constants.WATER_TEMPERATURE,
+                    "Przepływ [m3/s]": constants.DISCHARGE_DAILY_MEAN,
+                    "Stan wody [cm]": constants.STAGE_DAILY_MEAN,
+                    "Temperatura wody [st. C]": constants.WATER_TEMPERATURE_DAILY_MEAN,
                 }
             )
 
@@ -130,16 +130,16 @@ def _parse_all_data(self, raw_data_list: List[pd.DataFrame]) -> pd.DataFrame:
 
             # Select and convert variables
             var_cols = [
-                constants.DISCHARGE,
-                constants.STAGE,
-                constants.WATER_TEMPERATURE,
+                constants.DISCHARGE_DAILY_MEAN,
+                constants.STAGE_DAILY_MEAN,
+                constants.WATER_TEMPERATURE_DAILY_MEAN,
             ]
             for var in var_cols:
                 if var in full_df.columns:
                     full_df[var] = pd.to_numeric(full_df[var], errors="coerce")
 
-            if constants.STAGE in full_df.columns:
-                full_df[constants.STAGE] = full_df[constants.STAGE] / 100.0  # cm to m
+            if constants.STAGE_DAILY_MEAN in full_df.columns:
+                full_df[constants.STAGE_DAILY_MEAN] = full_df[constants.STAGE_DAILY_MEAN] / 100.0  # cm to m
 
             # Clean placeholder values
             full_df.replace({9999: None, 99999.999: None, 99.9: None, 999: None}, inplace=True)
diff --git a/rivretrieve/slovenia.py b/rivretrieve/slovenia.py
index 4fb0f44..f99dd81 100644
--- a/rivretrieve/slovenia.py
+++ b/rivretrieve/slovenia.py
@@ -25,7 +25,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_DAILY_MEAN)
 
     def _download_data(self, gauge_id: str, variable: str, start_date: str, end_date: str) -> Optional[str]:
         """Downloads the raw CSV data from the ARSO API."""
@@ -63,14 +63,14 @@ def _parse_data(self, gauge_id: str, raw_data: Optional[str], variable: str) ->
             df[constants.TIME_INDEX] = pd.to_datetime(df[constants.TIME_INDEX], format="%d.%m.%Y", errors="coerce")
             df = df.dropna(subset=[constants.TIME_INDEX])
 
-            if variable == constants.STAGE:
+            if variable == constants.STAGE_DAILY_MEAN:
                 raw_col = "vodostaj (cm)"
                 if raw_col in df.columns:
                     df[variable] = pd.to_numeric(df[raw_col], errors="coerce") / 100.0  # cm to m
                 else:
                     logger.warning(f"Column {raw_col} not found for site {gauge_id}")
                     return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
-            elif variable == constants.DISCHARGE:
+            elif variable == constants.DISCHARGE_DAILY_MEAN:
                 raw_col = "pretok (m3/s)"
                 if raw_col in df.columns:
                     df[variable] = pd.to_numeric(df[raw_col], errors="coerce")
diff --git a/rivretrieve/southafrica.py b/rivretrieve/southafrica.py
index 450e8ac..3973618 100644
--- a/rivretrieve/southafrica.py
+++ b/rivretrieve/southafrica.py
@@ -27,7 +27,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.DISCHARGE_INSTANT, constants.STAGE_INSTANT)
 
     def _construct_endpoint(
         self,
@@ -44,6 +44,16 @@ def _construct_endpoint(
         )
         return endpoint
 
+    def _get_variable_name(self, variable: str) -> str:
+        if variable == constants.DISCHARGE_DAILY_MEAN:
+            return "D_AVG_FR"
+        elif variable == constants.DISCHARGE_INSTANT:
+            return "COR_FLOW"
+        elif variable == constants.STAGE_INSTANT:
+            return "COR_LEVEL"
+        else:
+            raise ValueError(f"Unsupported variable: {variable}")
+
     def _download_data(
         self,
         gauge_id: str,
@@ -58,18 +68,18 @@ def _download_data(
         headers = {"User-Agent": "Mozilla/5.0"}
         data_list = []
 
-        if variable == constants.STAGE:
+        if variable in (constants.STAGE_INSTANT, constants.DISCHARGE_INSTANT):
             data_type = "Point"
             chunk_years = 1
             header = [
                 "DATE",
                 "TIME",
-                "COR_LEVEL",
+                "COR_LEVEL",  # Stage instant.
                 "COR_LEVEL_QUAL",
-                "COR_FLOW",
+                "COR_FLOW",  # Flow instant.
                 "COR_FLOW_QUAL",
             ]
-        elif variable == constants.DISCHARGE:  # discharge
+        elif variable == constants.DISCHARGE_DAILY_MEAN:  # discharge
             data_type = "Daily"
             chunk_years = 20
             header = ["DATE", "D_AVG_FR", "QUAL"]
@@ -139,23 +149,21 @@ def _parse_data(
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
         try:
-            full_df = pd.concat(raw_data_list, ignore_index=True)
-            if full_df.empty:
+            df = pd.concat(raw_data_list, ignore_index=True)
+            if df.empty:
                 return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
-            full_df[constants.TIME_INDEX] = pd.to_datetime(full_df["DATE"], format="%Y%m%d", errors="coerce")
-            full_df = full_df.dropna(subset=[constants.TIME_INDEX])
+            df[constants.TIME_INDEX] = pd.to_datetime(df["DATE"], format="%Y%m%d", errors="coerce")
+            df = (
+                df.dropna(subset=[constants.TIME_INDEX])
+                .sort_values(by=constants.TIME_INDEX)
+                .set_index(constants.TIME_INDEX)
+            )
 
-            if variable == constants.STAGE:
-                full_df["COR_LEVEL"] = pd.to_numeric(full_df["COR_LEVEL"], errors="coerce")
-                # Average stage if multiple readings per day
-                daily_df = full_df.groupby(constants.TIME_INDEX).agg(Value=("COR_LEVEL", "mean")).reset_index()
-            else:  # discharge
-                full_df["D_AVG_FR"] = pd.to_numeric(full_df["D_AVG_FR"], errors="coerce")
-                daily_df = full_df[[constants.TIME_INDEX, "D_AVG_FR"]].rename(columns={"D_AVG_FR": "Value"})
+            column = self._get_variable_name(variable)
+            df[column] = pd.to_numeric(df[column], errors="coerce")
 
-            daily_df = daily_df.rename(columns={"Value": variable})
-            return daily_df.dropna().sort_values(by=constants.TIME_INDEX).set_index(constants.TIME_INDEX)
+            return df.rename(columns={column: variable})
 
         except Exception as e:
             logger.error(f"Error parsing data for site {gauge_id}: {e}")
diff --git a/rivretrieve/uk_ea.py b/rivretrieve/uk_ea.py
index 808013e..2e30f5a 100644
--- a/rivretrieve/uk_ea.py
+++ b/rivretrieve/uk_ea.py
@@ -34,7 +34,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_15MIN)
 
     def get_metadata(self) -> pd.DataFrame:
         """Fetches site metadata for all stations from the EA API.
@@ -66,9 +66,9 @@ def get_metadata(self) -> pd.DataFrame:
 
     def _get_measure_notation(self, variable: str) -> str:
         """Gets the notation for the given variable."""
-        if variable == constants.STAGE:
+        if variable == constants.STAGE_15MIN:
             return "level-i-900-m-qualified"
-        elif variable == constants.DISCHARGE:
+        elif variable == constants.DISCHARGE_DAILY_MEAN:
             return "flow-m-86400-m3s-qualified"
         else:
             raise ValueError(f"Unsupported variable: {variable}")
@@ -129,7 +129,7 @@ def _download_data(self, gauge_id: str, variable: str, start_date: str, end_date
 
         return all_items
 
-    def _parse_data(self, gauge_id: str, raw_data: List[Dict[str, Any]], variable: str) -> pd.DataFrame:
+    def _parse_data(self, raw_data: List[Dict[str, Any]], variable: str) -> pd.DataFrame:
         """Parses the raw JSON data into a pandas DataFrame."""
         if not raw_data:
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
@@ -138,32 +138,22 @@ def _parse_data(self, gauge_id: str, raw_data: List[Dict[str, Any]], variable: s
         df[constants.TIME_INDEX] = pd.to_datetime(df["dateTime"]).dt.date
         df["Value"] = pd.to_numeric(df["value"], errors="coerce")
 
-        if variable == constants.STAGE:
-            # UK stage data is 15-min, average to daily
-            # A full day has 24 * 4 = 96 readings. We accept days with at least 90 readings.
-            min_readings = 90
-            df_daily = (
-                df.groupby(constants.TIME_INDEX).agg(Value=("Value", "mean"), Count=("Value", "size")).reset_index()
-            )
-            df_daily = df_daily[df_daily["Count"] >= min_readings]
-            df_daily = df_daily[[constants.TIME_INDEX, "Value"]]
-        else:  # discharge is already daily
-            df_daily = df[[constants.TIME_INDEX, "Value"]]
+        df = df[[constants.TIME_INDEX, "Value"]]
 
-        df_daily = df_daily.rename(columns={"Value": variable})
-        df_daily[constants.TIME_INDEX] = pd.to_datetime(df_daily[constants.TIME_INDEX])
+        df = df.rename(columns={"Value": variable})
+        df[constants.TIME_INDEX] = pd.to_datetime(df[constants.TIME_INDEX])
 
         # Ensure complete time series within the data range
-        if not df_daily.empty:
+        if not df.empty:
             date_range = pd.date_range(
-                start=df_daily[constants.TIME_INDEX].min(),
-                end=df_daily[constants.TIME_INDEX].max(),
+                start=df[constants.TIME_INDEX].min(),
+                end=df[constants.TIME_INDEX].max(),
                 freq="D",
             )
             complete_ts = pd.DataFrame(date_range, columns=[constants.TIME_INDEX])
-            df_daily = pd.merge(complete_ts, df_daily, on=constants.TIME_INDEX, how="left")
+            df = pd.merge(complete_ts, df, on=constants.TIME_INDEX, how="left")
 
-        return df_daily.set_index(constants.TIME_INDEX)
+        return df.set_index(constants.TIME_INDEX)
 
     def get_data(
         self,
@@ -180,7 +170,7 @@ def get_data(
 
         try:
             raw_data = self._download_data(gauge_id, variable, start_date, end_date)
-            df = self._parse_data(gauge_id, raw_data, variable)
+            df = self._parse_data(raw_data, variable)
 
             # Filter by exact start and end date after processing
             start_date_dt = pd.to_datetime(start_date)
diff --git a/rivretrieve/uk_nrfa.py b/rivretrieve/uk_nrfa.py
index 18747a4..9691a98 100644
--- a/rivretrieve/uk_nrfa.py
+++ b/rivretrieve/uk_nrfa.py
@@ -60,12 +60,12 @@ def get_metadata(self) -> pd.DataFrame:
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
         # Based on common NRFA data types, can be expanded
-        return (constants.DISCHARGE, constants.CATCHMENT_PRECIPITATION)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.CATCHMENT_PRECIPITATION_DAILY_SUM)
 
     def _get_nrfa_data_type(self, variable: str) -> str:
-        if variable == constants.DISCHARGE:
+        if variable == constants.DISCHARGE_DAILY_MEAN:
             return "gdf"  # Mean daily flow
-        elif variable == constants.CATCHMENT_PRECIPITATION:
+        elif variable == constants.CATCHMENT_PRECIPITATION_DAILY_SUM:
             return "cdr"  # Catchment daily precipitation.
         else:
             raise ValueError(f"Unsupported variable: {variable} for NRFA")
diff --git a/rivretrieve/usa.py b/rivretrieve/usa.py
index 0ded443..733594a 100644
--- a/rivretrieve/usa.py
+++ b/rivretrieve/usa.py
@@ -21,26 +21,56 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE, constants.STAGE)
+        return (
+            constants.DISCHARGE_DAILY_MEAN,
+            constants.DISCHARGE_INSTANT,
+            constants.STAGE_DAILY_MEAN,
+            constants.STAGE_DAILY_MAX,
+            constants.STAGE_DAILY_MIN,
+            constants.STAGE_INSTANT,
+        )
 
     def _get_param_code(self, variable: str) -> str:
-        if variable == constants.STAGE:
+        if constants.STAGE in variable:
             return "00065"
-        elif variable == constants.DISCHARGE:
+        elif constants.DISCHARGE in variable:
             return "00060"
         else:
             raise ValueError(f"Unsupported variable: {variable}")
 
+    def _get_column_name(self, variable: str) -> str:
+        param_code = self._get_param_code(variable)
+        if variable == constants.STAGE_DAILY_MAX:
+            return f"{param_code}_Maximum"
+        elif variable == constants.STAGE_DAILY_MIN:
+            return f"{param_code}_Minimum"
+        elif variable == constants.STAGE_DAILY_MEAN:
+            return f"{param_code}_Mean"
+        elif variable == constants.DISCHARGE_DAILY_MEAN:
+            return f"{param_code}_Mean"
+        elif variable == constants.DISCHARGE_INSTANT:
+            return param_code
+        elif variable == constants.STAGE_INSTANT:
+            return param_code
+
     def _download_data(self, gauge_id: str, variable: str, start_date: str, end_date: str) -> pd.DataFrame:
         """Downloads data using the dataretrieval package."""
         param_code = self._get_param_code(variable)
         try:
-            df, meta = nwis.get_dv(
-                sites=gauge_id,
-                startDT=start_date,
-                endDT=end_date,
-                parameterCd=[param_code],
-            )
+            if constants.DAILY in variable:
+                df, meta = nwis.get_dv(
+                    sites=gauge_id,
+                    startDT=start_date,
+                    endDT=end_date,
+                    parameterCd=[param_code],
+                )
+            elif constants.INSTANTANEOUS in variable:
+                df, meta = nwis.get_iv(
+                    sites=gauge_id,
+                    startDT=start_date,
+                    endDT=end_date,
+                    parameterCd=[param_code],
+                )
             return df
         except Exception as e:
             logger.error(f"Error fetching NWIS data for site {gauge_id}, param {param_code}: {e}")
@@ -53,15 +83,11 @@ def _parse_data(self, gauge_id: str, raw_data: pd.DataFrame, variable: str) -> p
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
         param_code = self._get_param_code(variable)
-
-        value_col = None
-        for col in raw_data.columns:
-            if col.startswith(param_code) and ("_Mean" in col or "_00003" in col):
-                value_col = col
-                break
-
-        if value_col is None:
-            logger.warning(f"Could not find value column for param {param_code} in data for site {gauge_id}")
+        value_col = self._get_column_name(variable)
+        if value_col not in raw_data.columns:
+            logger.warning(
+                f"Could not find value column {value_col} for param {param_code} in data for site {gauge_id}"
+            )
             return pd.DataFrame(columns=[constants.TIME_INDEX, variable])
 
         df = raw_data[[value_col]].copy()
@@ -70,9 +96,9 @@ def _parse_data(self, gauge_id: str, raw_data: pd.DataFrame, variable: str) -> p
         df[constants.TIME_INDEX] = pd.to_datetime(df[constants.TIME_INDEX].dt.date)
 
         # Unit conversion
-        if variable == constants.STAGE:  # Feet to meters
+        if variable.startswith(constants.STAGE):  # Feet to meters
             mult = 0.3048
-        elif variable == constants.DISCHARGE:  # cfs to m3/s
+        elif variable.startswith(constants.DISCHARGE):  # cfs to m3/s
             mult = 0.0283168466
         df[variable] = pd.to_numeric(df[value_col], errors="coerce") * mult
 
diff --git a/tests/test_australia.py b/tests/test_australia.py
index 9f63588..d12254a 100644
--- a/tests/test_australia.py
+++ b/tests/test_australia.py
@@ -37,7 +37,7 @@ def bom_request_side_effect(params):
         mock_make_bom_request.side_effect = bom_request_side_effect
 
         gauge_id = "405212"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2010-01-01"
         end_date = "2010-01-03"
 
@@ -45,7 +45,7 @@ def bom_request_side_effect(params):
 
         expected_data = {
             constants.TIME_INDEX: pd.to_datetime(["2010-01-01", "2010-01-02", "2010-01-03"]),
-            constants.DISCHARGE: [0.000, 3.710, 3.211],
+            constants.DISCHARGE_DAILY_MEAN: [0.000, 3.710, 3.211],
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_canada.py b/tests/test_canada.py
index 85c2079..3b879fb 100644
--- a/tests/test_canada.py
+++ b/tests/test_canada.py
@@ -24,7 +24,7 @@ def test_get_data_discharge(self, mock_hydat_path, mock_download, mock_requests)
         mock_download.return_value = True  # Prevent download attempt
 
         gauge_id = "08GA031"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2010-01-01"
         end_date = "2010-01-05"
 
@@ -34,7 +34,7 @@ def test_get_data_discharge(self, mock_hydat_path, mock_download, mock_requests)
             constants.TIME_INDEX: pd.to_datetime(
                 ["2010-01-01", "2010-01-02", "2010-01-03", "2010-01-04", "2010-01-05"]
             ),
-            constants.DISCHARGE: [1.1, 1.2, 1.3, 1.4, 1.5],
+            constants.DISCHARGE_DAILY_MEAN: [1.1, 1.2, 1.3, 1.4, 1.5],
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
@@ -50,7 +50,7 @@ def test_get_data_stage(self, mock_hydat_path, mock_download, mock_requests):
         mock_download.return_value = True  # Prevent download attempt
 
         gauge_id = "08GA031"
-        variable = constants.STAGE
+        variable = constants.STAGE_DAILY_MEAN
         start_date = "2010-01-01"
         end_date = "2010-01-05"
 
@@ -60,7 +60,7 @@ def test_get_data_stage(self, mock_hydat_path, mock_download, mock_requests):
             constants.TIME_INDEX: pd.to_datetime(
                 ["2010-01-01", "2010-01-02", "2010-01-03", "2010-01-04", "2010-01-05"]
             ),
-            constants.STAGE: [10.1, 10.2, 10.3, 10.4, 10.5],
+            constants.STAGE_DAILY_MEAN: [10.1, 10.2, 10.3, 10.4, 10.5],
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_chile.py b/tests/test_chile.py
index cd86075..09dd473 100644
--- a/tests/test_chile.py
+++ b/tests/test_chile.py
@@ -40,7 +40,7 @@ def get_side_effect(*args, **kwargs):
         mock_get.side_effect = get_side_effect
 
         gauge_id = "test_gauge"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2022-01-01"
         end_date = "2022-01-03"
 
@@ -48,7 +48,7 @@ def get_side_effect(*args, **kwargs):
 
         expected_data = {
             constants.TIME_INDEX: pd.to_datetime(["2022-01-01", "2022-01-02", "2022-01-03"]),
-            constants.DISCHARGE: [15.5, 16.0, 15.8],
+            constants.DISCHARGE_DAILY_MEAN: [15.5, 16.0, 15.8],
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_data/poland_test.zarr.zip b/tests/test_data/poland_test.zarr.zip
index 11b7a1e30eaf3549a06bb99cf2adef615cd7c417..29f63ebf84b48f4d157df683a191a4a931d9b6ab 100644
GIT binary patch
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diff --git a/tests/test_france.py b/tests/test_france.py
index 6d5701e..9cc540b 100644
--- a/tests/test_france.py
+++ b/tests/test_france.py
@@ -28,7 +28,7 @@ def test_get_data_discharge(self, mock_get):
         mock_get.return_value = mock_response
 
         gauge_id = "Y1220010"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2023-01-01"
         end_date = "2023-01-03"
 
@@ -36,7 +36,7 @@ def test_get_data_discharge(self, mock_get):
 
         expected_data = {
             constants.TIME_INDEX: pd.to_datetime(["2023-01-01", "2023-01-02", "2023-01-03"]),
-            constants.DISCHARGE: [15.0005, 16.0000, 15.5002],  # Divided by 1000
+            constants.DISCHARGE_DAILY_MEAN: [15.0005, 16.0000, 15.5002],  # Divided by 1000
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_japan.py b/tests/test_japan.py
index 423c65b..906795c 100644
--- a/tests/test_japan.py
+++ b/tests/test_japan.py
@@ -28,7 +28,7 @@ def test_get_data_discharge(self, mock_get):
         mock_get.return_value = mock_response
 
         gauge_id = "301011281104010"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2019-01-13"
         end_date = "2019-01-17"
 
@@ -38,7 +38,7 @@ def test_get_data_discharge(self, mock_get):
         expected_values = [2.09, 1.78, 1.78, 2.09, 1.78]
         expected_data = {
             constants.TIME_INDEX: expected_dates,
-            constants.DISCHARGE: expected_values,
+            constants.DISCHARGE_DAILY_MEAN: expected_values,
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_poland.py b/tests/test_poland.py
index 22e1681..1dd2061 100644
--- a/tests/test_poland.py
+++ b/tests/test_poland.py
@@ -34,7 +34,7 @@ def tearDown(self):
     def test_get_data_discharge(self, mock_create_cache):
         with patch("rivretrieve.poland.PolandFetcher.CACHE_FILE", self.test_cache_file):
             gauge_id = "149180010"
-            variable = constants.DISCHARGE
+            variable = constants.DISCHARGE_DAILY_MEAN
             start_date = "2020-01-01"
             end_date = "2020-01-05"
 
@@ -44,7 +44,7 @@ def test_get_data_discharge(self, mock_create_cache):
             expected_values = [45.9, 41.0, 39.3, 37.5, 38.1]
             expected_data = {
                 constants.TIME_INDEX: expected_dates,
-                constants.DISCHARGE: expected_values,
+                constants.DISCHARGE_DAILY_MEAN: expected_values,
             }
             expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
@@ -55,7 +55,7 @@ def test_get_data_discharge(self, mock_create_cache):
     def test_get_data_stage(self, mock_create_cache):
         with patch("rivretrieve.poland.PolandFetcher.CACHE_FILE", self.test_cache_file):
             gauge_id = "149180010"
-            variable = constants.STAGE
+            variable = constants.STAGE_DAILY_MEAN
             start_date = "2020-01-03"
             end_date = "2020-01-07"
 
@@ -65,7 +65,7 @@ def test_get_data_stage(self, mock_create_cache):
             expected_values = [1.19, 1.16, 1.17, 1.12, 1.07]
             expected_data = {
                 constants.TIME_INDEX: expected_dates,
-                constants.STAGE: expected_values,
+                constants.STAGE_DAILY_MEAN: expected_values,
             }
             expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
@@ -128,9 +128,9 @@ def mock_get_side_effect(url, *args, **kwargs):
         self.assertGreater(len(parsed_df), 20000)  # Expect many rows from two months of data
         self.assertIn(constants.GAUGE_ID, parsed_df.columns)
         self.assertIn(constants.TIME_INDEX, parsed_df.columns)
-        self.assertIn(constants.DISCHARGE, parsed_df.columns)
-        self.assertIn(constants.STAGE, parsed_df.columns)
-        self.assertIn(constants.WATER_TEMPERATURE, parsed_df.columns)
+        self.assertIn(constants.DISCHARGE_DAILY_MEAN, parsed_df.columns)
+        self.assertIn(constants.STAGE_DAILY_MEAN, parsed_df.columns)
+        self.assertIn(constants.WATER_TEMPERATURE_DAILY_MEAN, parsed_df.columns)
 
         # Check date range
         self.assertEqual(parsed_df[constants.TIME_INDEX].min(), pd.to_datetime("2022-01-01"))
diff --git a/tests/test_slovenia.py b/tests/test_slovenia.py
index c254f29..6c69859 100644
--- a/tests/test_slovenia.py
+++ b/tests/test_slovenia.py
@@ -33,7 +33,7 @@ def test_get_data_discharge(self, mock_requests_session):
         mock_session.get.return_value = mock_response
 
         gauge_id = "1020"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "1980-01-01"
         end_date = "1980-01-05"
 
@@ -43,7 +43,7 @@ def test_get_data_discharge(self, mock_requests_session):
         expected_values = [115.0, 119.0, 115.0, 108.0, 108.0]  # Values from sample file
         expected_data = {
             constants.TIME_INDEX: expected_dates,
-            constants.DISCHARGE: expected_values,
+            constants.DISCHARGE_DAILY_MEAN: expected_values,
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
@@ -65,7 +65,7 @@ def test_get_data_stage(self, mock_requests_session):
         mock_session.get.return_value = mock_response
 
         gauge_id = "1020"
-        variable = constants.STAGE
+        variable = constants.STAGE_DAILY_MEAN
         start_date = "1980-01-01"
         end_date = "1980-01-03"
 
@@ -79,7 +79,7 @@ def test_get_data_stage(self, mock_requests_session):
         ]  # Values from sample file / 100
         expected_data = {
             constants.TIME_INDEX: expected_dates,
-            constants.STAGE: expected_values,
+            constants.STAGE_DAILY_MEAN: expected_values,
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_southafrica.py b/tests/test_southafrica.py
index ea59a9d..b4ce620 100644
--- a/tests/test_southafrica.py
+++ b/tests/test_southafrica.py
@@ -24,14 +24,14 @@ def test_get_data_nodata(self, mock_requests_session):
         mock_session.get.return_value = mock_response
 
         gauge_id = "X3H023"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2022-01-01"
         end_date = "2022-01-05"
 
         result_df = self.fetcher.get_data(gauge_id, variable, start_date, end_date)
 
         self.assertTrue(result_df.empty)
-        self.assertEqual(list(result_df.columns), [constants.TIME_INDEX, constants.DISCHARGE])
+        self.assertEqual(list(result_df.columns), [constants.TIME_INDEX, constants.DISCHARGE_DAILY_MEAN])
         mock_session.get.assert_called_once()
 
     # TODO: Add tests with actual data when sample is available
diff --git a/tests/test_uk_ea.py b/tests/test_uk_ea.py
index 0679e1f..5fe4563 100644
--- a/tests/test_uk_ea.py
+++ b/tests/test_uk_ea.py
@@ -49,7 +49,7 @@ def mock_get_side_effect(url, *args, **kwargs):
         mock_session.get.side_effect = mock_get_side_effect
 
         gauge_id = "http://environment.data.gov.uk/hydrology/id/stations/3c5cba29-2321-4289-a1fd-c355e135f4cb"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2024-01-01"
         end_date = "2024-01-03"
 
@@ -59,7 +59,7 @@ def mock_get_side_effect(url, *args, **kwargs):
         expected_values = [72.777, 99.138, 68.020]  # Values from sample file
         expected_data = {
             constants.TIME_INDEX: expected_dates,
-            constants.DISCHARGE: expected_values,
+            constants.DISCHARGE_DAILY_MEAN: expected_values,
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 
diff --git a/tests/test_uk_nrfa.py b/tests/test_uk_nrfa.py
index 56bc1d9..52620a7 100644
--- a/tests/test_uk_nrfa.py
+++ b/tests/test_uk_nrfa.py
@@ -68,13 +68,13 @@ def test_get_metadata(self, mock_requests_session):
     @parameterized.expand(
         [
             (
-                constants.DISCHARGE,
+                constants.DISCHARGE_DAILY_MEAN,
                 "gdf",
                 "uk_nrfa_1001_discharge_20220101.json",
                 [1.552, 1.461, 2.035, 7.232, 6.539],
             ),
             (
-                constants.CATCHMENT_PRECIPITATION,
+                constants.CATCHMENT_PRECIPITATION_DAILY_SUM,
                 "cdr",
                 "uk_nrfa_1001_precipitation_20220101.json",
                 [0.2, 1.7, 4.4, 9.1, 0.2],
diff --git a/tests/test_usa.py b/tests/test_usa.py
index e7a16a2..85d80b4 100644
--- a/tests/test_usa.py
+++ b/tests/test_usa.py
@@ -32,7 +32,7 @@ def test_get_data_discharge(self, mock_get_dv):
         )  # get_dv returns df and metadata
 
         gauge_id = "07374000"
-        variable = constants.DISCHARGE
+        variable = constants.DISCHARGE_DAILY_MEAN
         start_date = "2023-01-01"
         end_date = "2023-01-05"
 
@@ -49,7 +49,7 @@ def test_get_data_discharge(self, mock_get_dv):
         ]
         expected_data = {
             constants.TIME_INDEX: expected_dates,
-            constants.DISCHARGE: expected_values,
+            constants.DISCHARGE_DAILY_MEAN: expected_values,
         }
         expected_df = pd.DataFrame(expected_data).set_index(constants.TIME_INDEX)
 

From 8ddc519d861074574cb5ce36638a360d50662cf7 Mon Sep 17 00:00:00 2001
From: Frederik Kratzert <f.kratzert@gmail.com>
Date: Fri, 17 Oct 2025 10:44:52 +0000
Subject: [PATCH 3/3] Change 15min name to instantaneous

---
 rivretrieve/constants.py | 4 ----
 rivretrieve/uk_ea.py     | 4 ++--
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/rivretrieve/constants.py b/rivretrieve/constants.py
index f76dc2f..ad16ac0 100644
--- a/rivretrieve/constants.py
+++ b/rivretrieve/constants.py
@@ -22,8 +22,6 @@
 
 # List of temporal resolutions.
 DAILY = "daily"
-_HOURLY = "60min"
-_15MIN = "15min"
 INSTANTANEOUS = "instantaneous"
 
 # List of temporal aggregrations.
@@ -38,14 +36,12 @@
 DISCHARGE_DAILY_MEAN = f"{DISCHARGE}_{DAILY}_{_MEAN}"
 DISCHARGE_DAILY_MAX = f"{DISCHARGE}_{DAILY}_{_MAX}"
 DISCHARGE_DAILY_MIN = f"{DISCHARGE}_{DAILY}_{_MIN}"
-DISCHARGE_15MIN = f"{DISCHARGE}_{_15MIN}"
 DISCHARGE_INSTANT = f"{DISCHARGE}_{INSTANTANEOUS}"
 
 # Stage.
 STAGE_DAILY_MEAN = f"{STAGE}_{DAILY}_{_MEAN}"
 STAGE_DAILY_MAX = f"{STAGE}_{DAILY}_{_MAX}"
 STAGE_DAILY_MIN = f"{STAGE}_{DAILY}_{_MIN}"
-STAGE_15MIN = f"{STAGE}_{_15MIN}"
 STAGE_INSTANT = f"{STAGE}_{INSTANTANEOUS}"
 
 # Water temperature.
diff --git a/rivretrieve/uk_ea.py b/rivretrieve/uk_ea.py
index 2e30f5a..986954f 100644
--- a/rivretrieve/uk_ea.py
+++ b/rivretrieve/uk_ea.py
@@ -34,7 +34,7 @@ def get_gauge_ids() -> pd.DataFrame:
 
     @staticmethod
     def get_available_variables() -> tuple[str, ...]:
-        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_15MIN)
+        return (constants.DISCHARGE_DAILY_MEAN, constants.STAGE_INSTANT)
 
     def get_metadata(self) -> pd.DataFrame:
         """Fetches site metadata for all stations from the EA API.
@@ -66,7 +66,7 @@ def get_metadata(self) -> pd.DataFrame:
 
     def _get_measure_notation(self, variable: str) -> str:
         """Gets the notation for the given variable."""
-        if variable == constants.STAGE_15MIN:
+        if variable == constants.STAGE_INSTANT:
             return "level-i-900-m-qualified"
         elif variable == constants.DISCHARGE_DAILY_MEAN:
             return "flow-m-86400-m3s-qualified"