diff --git a/ush/wdqms.py b/ush/wdqms.py
index 4bc886ad7b..5917499cd0 100755
--- a/ush/wdqms.py
+++ b/ush/wdqms.py
@@ -66,6 +66,10 @@ def __init__(self, inputfiles, wdqms_type, outdir,
         # Grab actual datetimes from datetime + timedelta
         df_total = self._get_datetimes(df_total)
 
+        # Drop duplicates
+        columns_to_compare = ['Station_ID', 'var_id', 'Observation_Type', 'Latitude', 'Longitude', 'Pressure', 'Time']
+        df_total = df_total.drop_duplicates(subset=columns_to_compare, keep='first')
+
         # Adjust relative humidity data
         df_total = self._genqsat(df_total)
 
@@ -474,10 +478,13 @@ def _genqsat(self, df):
             t_tmp = t_df.loc[(t_df['Station_ID'] == stn)]
             q_tmp = q_df.loc[(q_df['Station_ID'] == stn)]
 
-            t_tmp = t_tmp.loc[(np.in1d(t_tmp['Time'], q_tmp['Time'])) &
-                              (np.in1d(t_tmp['Pressure'], q_tmp['Pressure'])) &
-                              (np.in1d(t_tmp['Latitude'], q_tmp['Latitude'])) &
-                              (np.in1d(t_tmp['Longitude'], q_tmp['Longitude']))]
+            columns_to_extract = ['Latitude', 'Longitude', 'Pressure', 'Time', 'Observation', 'Obs_Minus_Forecast_adjusted']
+            columns_to_compare = ['Latitude', 'Longitude', 'Pressure', 'Time']
+
+            t_tmp = t_tmp[columns_to_extract]
+            q_tmp = q_tmp[columns_to_extract]
+
+            t_tmp = pd.merge(t_tmp, q_tmp, on=columns_to_compare, suffixes=('','_q'), how='inner')
 
             q_obs = q_tmp['Observation'].to_numpy() * 1.0e6
             q_ges = (q_tmp['Observation'].to_numpy() -