diff --git a/cea/config.py b/cea/config.py
index 5be62c2009..0d1cba7c05 100644
--- a/cea/config.py
+++ b/cea/config.py
@@ -561,6 +561,13 @@ def decode(self, value):
             weather_path = self.locator.get_weather(value)
         elif os.path.exists(value) and value.endswith('.epw'):
             weather_path = value
+        elif os.path.exists(value) and value.endswith('.dat'):
+            # if dat convert to epw
+            dat_weather_file = value
+            epw_weather_file = os.path.join(os.path.dirname(value), os.path.basename(value).replace('.dat', '.epw'))
+            from cea.datamanagement.weather_helper import parse_dat_weather_file
+            parse_dat_weather_file(dat_weather_file, epw_weather_file)
+            weather_path = epw_weather_file
         elif any(w.lower().startswith(value.lower()) for w in self.locator.get_weather_names()) and value.strip():
             # allow using shortcuts
             weather_path = self.locator.get_weather(
@@ -568,7 +575,7 @@ def decode(self, value):
         elif value in self.THIRD_PARTY_WEATHER_SOURCES:
             weather_path = value
         else:
-            raise cea.ConfigError(f"Invalid weather path: {value}")
+            raise cea.ConfigError(f"Invalid weather path: {value}. Supported formats: .epw, .dat")
         return weather_path
 
     @property
diff --git a/cea/datamanagement/weather_helper/generate_weather_data_sources.py b/cea/datamanagement/weather_helper/generate_weather_data_sources.py
index a6a82c2cc0..286231fb1e 100644
--- a/cea/datamanagement/weather_helper/generate_weather_data_sources.py
+++ b/cea/datamanagement/weather_helper/generate_weather_data_sources.py
@@ -22,7 +22,6 @@
 
 WEATHER_DATA_LOCATION = os.path.join(os.path.realpath(os.path.dirname(__file__)), 'weather.geojson')
 
-
 def main():
     # Combine for global data
     excels = [pd.read_excel(url) for url in URL_LIST]
diff --git a/cea/datamanagement/weather_helper/weather_helper.py b/cea/datamanagement/weather_helper/weather_helper.py
index 00f3f4e658..4ef485f4d4 100644
--- a/cea/datamanagement/weather_helper/weather_helper.py
+++ b/cea/datamanagement/weather_helper/weather_helper.py
@@ -74,6 +74,47 @@ def copy_weather_file(source_weather_file, locator):
         source_weather_file=source_weather_file
     ))
 
+def parse_dat_weather_file(source_dat_file, output_epw_file):
+    """
+    convert a DWD .dat-file to a epw-file
+
+    :param string source_dat_file: source .dat
+    :param string output_epw_file: output EPW
+    """
+    import pandas as pd
+
+    print(f"Parsing .dat file: {source_dat_file}")
+    try:
+        weather_data = pd.read_csv(source_dat_file, sep="\s+", skiprows=6, header=None)
+        weather_data.columns = ['RW', 'HW', 'MM', 'DD', 'HH', 't', 'p', 'WR', 'WG', 'N', 'x', 'RF', 'B', 'D', 'A', 'E',
+                                'IL']
+
+        # from dat to epw
+        with open(output_epw_file, 'w') as epw_file:
+            epw_file.write("LOCATION,Weimar,-,DEU,SRC-TMYx,105550,50.983,11.317,1,268\n")
+            epw_file.write("DESIGN CONDITIONS,0\n")
+            epw_file.write("TYPICAL/EXTREME PERIODS,0\n")
+            epw_file.write("GROUND TEMPERATURES,0\n")
+            epw_file.write("HOLIDAYS/DAYLIGHT SAVINGS,No,0,0,0\n")
+            epw_file.write("COMMENTS 1, converted from .dat to .epw by CEA\n")
+            epw_file.write("COMMENTS 2\n")
+            epw_file.write("DATA PERIODS,1,1,Data,Tuesday,1/1,12/31\n")
+
+            for _, row in weather_data.iterrows():
+                mm = int(row['MM'])
+                dd = int(row['DD'])
+                hh = int(row['HH'])
+                epw_line = f"1958,{mm},{dd},{hh},60,B8E7B8B8?9?0?0?0?0?0?0B8B8B8B8?0?0F8F8A7E7, " \
+                           f"{row['t']},99,99,{row['RF']}, {row['p']}, 9999, {row['A']}, {row['D']}, {row['B']}, {row['D']}," \
+                           f"-9999, -9999, -9999, -9999,{row['WR']}, {row['WG']}, 99, 9999, 9999, 9999,0, 999999999,0," \
+                           f" -999,-999,-999\n"
+                epw_file.write(epw_line)
++    except pd.errors.EmptyDataError as e:
++        raise ValueError("The .dat file is empty or has incorrect format") from e
++    except pd.errors.ParserError as e:
++        raise ValueError("Failed to parse the .dat file - invalid format") from e
++    except Exception as e:
++        raise ValueError(f"Unexpected error while parsing .dat file: {str(e)}") from e
 
 def main(config):
     """
@@ -85,7 +126,13 @@ def main(config):
     locator = cea.inputlocator.InputLocator(config.scenario)
     weather = config.weather_helper.weather
 
-    if config.weather_helper.weather == 'climate.onebuilding.org':
+    if weather.endswith('.dat'):
+        print(f"Detected .dat file: {weather}")
+        # convert .dat in .epw
+        dat_weather_file = weather
+        epw_weather_file = locator.get_weather_file()
+        parse_dat_weather_file(dat_weather_file, epw_weather_file)
+    elif config.weather_helper.weather == 'climate.onebuilding.org':
         print("No weather provided, fetching from online sources.")
         fetch_weather_data(locator.get_weather_file(), locator.get_zone_geometry())
     else:
diff --git a/cea/default.config b/cea/default.config
index 785add0b2d..9790d8c0f5 100644
--- a/cea/default.config
+++ b/cea/default.config
@@ -132,7 +132,7 @@ trees.help = Path to shapefile containing the geometries of tree canopies in pol
 [weather-helper]
 weather =
 weather.type = WeatherPathParameter
-weather.help = Either a full path to a weather file (.epw) or the name of one of the weather files contained within the CEA. Leave blank to fetch from third-party sources.
+weather.help = Either a full path to a weather file (.epw or .dat) or the name of one of the weather files contained within the CEA. Leave blank to fetch from third-party sources.
 
 [radiation]
 buildings =