diff --git a/example/modelchain_example.ipynb b/example/modelchain_example.ipynb
index 14714a2f..f4b1f748 100644
--- a/example/modelchain_example.ipynb
+++ b/example/modelchain_example.ipynb
@@ -139,11 +139,6 @@
     "    weather_df.index = pd.to_datetime(weather_df.index).tz_convert(\n",
     "        'Europe/Berlin')\n",
     "    \n",
-    "    # change type of height from str to int by resetting columns\n",
-    "    l0 = [_[0] for _ in weather_df.columns]\n",
-    "    l1 = [int(_[1]) for _ in weather_df.columns]\n",
-    "    weather_df.columns = [l0, l1]\n",
-    "    \n",
     "    return weather_df\n",
     "\n",
     "\n",
diff --git a/example/modelchain_example.py b/example/modelchain_example.py
index c4686e61..acf85b8e 100644
--- a/example/modelchain_example.py
+++ b/example/modelchain_example.py
@@ -83,11 +83,6 @@ def get_weather_data(filename='weather.csv', **kwargs):
         "Europe/Berlin"
     )
 
-    # change type of height from str to int by resetting columns
-    l0 = [_[0] for _ in weather_df.columns]
-    l1 = [int(_[1]) for _ in weather_df.columns]
-    weather_df.columns = [l0, l1]
-
     return weather_df
 
 
diff --git a/tests/test_turbine_cluster_modelchain.py b/tests/test_turbine_cluster_modelchain.py
index 2b20e151..8a827978 100644
--- a/tests/test_turbine_cluster_modelchain.py
+++ b/tests/test_turbine_cluster_modelchain.py
@@ -358,3 +358,21 @@ def test_tc_modelchain_with_power_curve_as_dict(self):
         )
         test_tc_mc.run_model(self.weather_df)
         assert_series_equal(test_tc_mc.power_output, power_output_exp)
+
+    def test_heigths_as_string(self):
+        """Test run_model if data heights are of type string."""
+
+        # Convert data heights to str
+        string_weather = self.weather_df.copy()
+        string_weather.columns = pd.MultiIndex.from_arrays([
+            string_weather.columns.get_level_values(0),
+            string_weather.columns.get_level_values(1).astype(str)])
+
+        # Heights in the original DataFrame are of type np.int64
+        assert isinstance(self.weather_df.columns.get_level_values(1)[0],
+                          np.int64)
+        assert isinstance(string_weather.columns.get_level_values(1)[0], str)
+
+        test_mc = tc_mc.TurbineClusterModelChain(
+            power_plant=wtc.WindTurbineCluster(**self.test_cluster))
+        test_mc.run_model(string_weather)
diff --git a/windpowerlib/turbine_cluster_modelchain.py b/windpowerlib/turbine_cluster_modelchain.py
index 5e0eeba1..a72ae52a 100644
--- a/windpowerlib/turbine_cluster_modelchain.py
+++ b/windpowerlib/turbine_cluster_modelchain.py
@@ -8,6 +8,7 @@
 SPDX-License-Identifier: MIT
 """
 import logging
+import pandas as pd
 from windpowerlib import wake_losses
 from windpowerlib.modelchain import ModelChain
 
@@ -288,6 +289,10 @@ def run_model(self, weather_df):
         'wind_speed'
 
         """
+        # Convert data heights to integer. In some case they are strings.
+        weather_df.columns = pd.MultiIndex.from_arrays([
+            weather_df.columns.get_level_values(0),
+            pd.to_numeric(weather_df.columns.get_level_values(1))])
 
         self.assign_power_curve(weather_df)
         self.power_plant.mean_hub_height()