diff --git a/mlair/helpers/filter.py b/mlair/helpers/filter.py
index 3f5ee5f3e8b2d9682fc0f3d1780da7870d64e1fd..30e8132089615bd7d08b9c25c03201d7439723c2 100644
--- a/mlair/helpers/filter.py
+++ b/mlair/helpers/filter.py
@@ -391,6 +391,8 @@ def fir_filter(data, fs, order=5, cutoff_low=None, cutoff_high=None, window="ham
 def fir_filter_numpy_vectorized(filter_input_data, var_dim, kwargs):
     filt_np = xr.DataArray(np.nan, coords=filter_input_data.coords)
     for var in filter_input_data.coords[var_dim]:
+        logging.info(
+            f"{filter_input_data.coords['Stations'].values[0]}: {str(var.values)}")  # ToDo must be removed, just for debug
         a = np.apply_along_axis(fir_filter_vectorized, 2, filter_input_data.sel({var_dim: var}).values, **kwargs)
         filt_np.loc[{var_dim: var}] = a
     return filt_np