diff --git a/ush/SpatialTemporalStatsTool/user_Analysis.py b/ush/SpatialTemporalStatsTool/user_Analysis.py
index 82d7d64..8955405 100644
--- a/ush/SpatialTemporalStatsTool/user_Analysis.py
+++ b/ush/SpatialTemporalStatsTool/user_Analysis.py
@@ -123,7 +123,7 @@ def parse_filter(s):
     parser.add_argument(
         "-g",
         dest="grid_size",
-        help=r"optional: size of grid for plotting",
+        help=r"optional: size of grid for plotting: 1: 1X1 degree(default), 2:2X2 degree, 3:3X3 degree",
         required=False,
         default=1,
         metavar="float",