diff --git a/mlair/data_handler/data_handler_wrf_chem.py b/mlair/data_handler/data_handler_wrf_chem.py
index 15837977c7a0c8f937daa697075134ab9d44b7d5..2d0ea525be9340b2065397eb5e78d41ae202655a 100644
--- a/mlair/data_handler/data_handler_wrf_chem.py
+++ b/mlair/data_handler/data_handler_wrf_chem.py
@@ -1253,7 +1253,8 @@ class DataHandlerSectorGrid(DataHandlerSingleGridColumn):
                                  f"data/{self.station[0]}_{self.start}_{self.end}_upstream_wind_sector.nc")
         wind_upstream_sector_by_name = self.wind_upstream_sector_by_name
         dims_to_expand = list(wind_upstream_sector_by_name.coords._names - set(wind_upstream_sector_by_name.dims))
-        wind_upstream_sector_by_name = wind_upstream_sector_by_name.expand_dims(dims_to_expand)
+        wind_upstream_sector_by_name = wind_upstream_sector_by_name.expand_dims(dims_to_expand).squeeze(
+            dim=list(set(dims_to_expand) - {self.iter_dim, self.target_dim}))
         wind_upstream_sector_by_name = wind_upstream_sector_by_name.to_dataset(self.iter_dim)
         wind_upstream_sector_by_name.to_netcdf(file_name)