diff --git a/modules/util/lon_lat_grid.py b/modules/util/lon_lat_grid.py
index 1b4e65fa170017e8a389531db1e4bb6f09e2be05..d1a4e724070bb7ade28e1ac58c3058fa5f6837a4 100644
--- a/modules/util/lon_lat_grid.py
+++ b/modules/util/lon_lat_grid.py
@@ -190,6 +190,8 @@ class LonLatGrid:
         return outv
 
     def check_inside(self, lon, lat):
+        if lon < 0:
+            lon += 360
         return (self.lon_lo < lon < self.lon_hi) & (self.lat_lo < lat < self.lat_hi)