diff --git a/src/smhi/constants.py b/src/smhi/constants.py
index d36e5add..2031478d 100644
--- a/src/smhi/constants.py
+++ b/src/smhi/constants.py
@@ -21,12 +21,12 @@ def get_now() -> datetime:
     return arrow.utcnow().datetime  # .isoformat("T", "seconds") + "Z"
 
 
-METOBS_AVAILABLE_PERIODS = [
-    "latest-hour",
-    "latest-day",
-    "latest-months",
-    "corrected-archive",
-]
+METOBS_AVAILABLE_PERIODS = {
+    "latest-hour": 0,
+    "latest-day": 1,
+    "latest-months": 2,
+    "corrected-archive": 3,
+}
 
 METFCTS_URL = (
     "https://opendata-download-metfcst.smhi.se/"
diff --git a/src/smhi/metobs.py b/src/smhi/metobs.py
index f17aa0a5..141ca62a 100644
--- a/src/smhi/metobs.py
+++ b/src/smhi/metobs.py
@@ -298,7 +298,7 @@ def __init__(
 class Data(BaseMetobs):
     """Get data from period for version 1 of Metobs API."""
 
-    _metobs_available_periods: Dict[str, str] = METOBS_AVAILABLE_PERIODS
+    _metobs_available_periods: Dict[str, int] = METOBS_AVAILABLE_PERIODS
     _metobs_parameter_tim: List[str] = ["Datum", "Tid (UTC)"]
     _metobs_parameter_dygn: List[str] = ["Representativt dygn"]
     _metobs_parameter_manad: List[str] = ["Representativ månad"]
@@ -323,21 +323,13 @@ def __init__(
         """
         super().__init__()
 
-        if period is None:
-            ordering = {
-                "latest-hour": 0,
-                "latest-day": 1,
-                "latest-months": 2,
-                "corrected-archive": 3,
-            }
-            available_periods = sorted(
-                periods_in_station.data, key=lambda x: ordering.__getitem__(x)
-            )
-            period = available_periods[0]
-
         if data_type != "json":
             raise TypeError("Only json supported.")
 
+        if period is None:
+            period = periods_in_station.data[0]
+            logger.info("No period selected, selecting: {period}.")
+
         if self._check_available_periods(periods_in_station.data, period):
             logger.info(
                 "Found only one period to download. "
@@ -347,8 +339,8 @@ def __init__(
 
         if period not in self._metobs_available_periods:
             raise NotImplementedError(
-                "Select a supported periods: }"
-                + ", ".join([p for p in self._metobs_available_periods])
+                "Select a supported period: "
+                + ", ".join([p for p in self._metobs_available_periods.keys()])
             )
 
         self.periods_in_station = periods_in_station
diff --git a/src/smhi/models/metobs_model.py b/src/smhi/models/metobs_model.py
index a482ebd7..4743e592 100644
--- a/src/smhi/models/metobs_model.py
+++ b/src/smhi/models/metobs_model.py
@@ -4,6 +4,7 @@
 
 import pandas as pd
 from pydantic import BaseModel, ConfigDict, Field, field_validator
+from smhi.constants import METOBS_AVAILABLE_PERIODS
 
 
 class MetobsLink(BaseModel):
@@ -183,7 +184,7 @@ class MetobsStationModel(MetobsBaseModel):
     @field_validator("period")
     @classmethod
     def serialise_period_in_order(cls, period: List[MetobsLinks]):
-        return sorted(period, key=lambda x: x.key)
+        return sorted(period, key=lambda x: METOBS_AVAILABLE_PERIODS[x.key])
 
     @property
     def data(self) -> Tuple[Optional[str], ...]:
diff --git a/tests/unit/test_unit_smhi.py b/tests/unit/test_unit_smhi.py
index 00b03178..23951b15 100644
--- a/tests/unit/test_unit_smhi.py
+++ b/tests/unit/test_unit_smhi.py
@@ -35,8 +35,8 @@ def __init__(self, data="str"):
 
 
 @pytest.fixture
-def setup_test_x():
-    """Pytest fixture"""
+def setup_iterate_over_time():
+    """Iterate over time fixture."""
     df = pd.DataFrame(
         {
             "date": [
@@ -108,7 +108,7 @@ def test_unit_smhi_get_stations_from_title(
     @patch("smhi.metobs.Stations.__new__")
     @patch("smhi.metobs.Periods.__new__")
     @patch("smhi.metobs.Data.__new__")
-    @patch("smhi.smhi.SMHI._interpolate")
+    @patch("smhi.smhi.SMHI._interpolate", return_value="test")
     def test_unit_get_data(
         self,
         mock_interpolate,
@@ -130,7 +130,6 @@ def test_unit_get_data(
             station,
             distance,
         """
-        mock_interpolate.return_value = "test"
         client = SMHI()
         data = client.get_data(parameter, station, distance)
         assert data == "test"
@@ -142,7 +141,7 @@ def test_unit_get_data(
     @patch("smhi.metobs.Periods.__new__")
     @patch("smhi.metobs.Data.__new__")
     @patch("smhi.smhi.SMHI._find_stations_by_city")
-    @patch("smhi.smhi.SMHI._interpolate")
+    @patch("smhi.smhi.SMHI._interpolate", return_value="test")
     def test_unit_get_data_by_city(
         self,
         mock_interpolate,
@@ -166,7 +165,6 @@ def test_unit_get_data_by_city(
             city,
             distance
         """
-        mock_interpolate.return_value = "test"
         client = SMHI()
         data = client.get_data_by_city(parameter, city, distance)
         assert data == "test"
@@ -232,6 +230,7 @@ def test_find_stations_by_city(
         client = SMHI()
         _ = client._find_stations_by_city(parameter, city, distance)
         mock_nominatim.assert_called_once()
+        mock_find_from_gps.assert_called_once()
 
     @pytest.mark.parametrize("distance", [(0), (50)])
     @patch("smhi.metobs.Stations.__new__")
@@ -270,17 +269,15 @@ def test_interpolate(
         else:
             mock_find_from_gps.assert_called_once()
 
-    def test_iterate_over_time(self, setup_test_x):
+    def test_iterate_over_time(self, setup_iterate_over_time):
         """Unit test for SMHI _iterate_over_time method."""
-        df, nearby_df, missing_df = setup_test_x
+        df, nearby_df, missing_df = setup_iterate_over_time
         client = SMHI()
 
         data = client._iterate_over_time(df, nearby_df, missing_df)
         assert data.tail(2).iloc[0]["Temperatur"] == nearby_df.iloc[0]["Temperatur"]
 
-    def test_find_missing_data(
-        self,
-    ):
+    def test_find_missing_data(self):
         """Unit test for SMHI _find_missing_data method."""
         df = pd.DataFrame(
             {