diff --git a/lib/microwaveprop/propagation.ex b/lib/microwaveprop/propagation.ex
index b3230264..bcb0ae40 100644
--- a/lib/microwaveprop/propagation.ex
+++ b/lib/microwaveprop/propagation.ex
@@ -22,8 +22,9 @@ defmodule Microwaveprop.Propagation do
     temp_c = hrrr_profile.surface_temp_c
     dewpoint_c = hrrr_profile.surface_dewpoint_c
 
-    # Skip points with missing surface data (ocean/outside-domain)
-    if is_nil(temp_c) or is_nil(dewpoint_c) do
+    # Skip points with missing or physically impossible surface data
+    if is_nil(temp_c) or is_nil(dewpoint_c) or temp_c < -80 or temp_c > 60 or
+         dewpoint_c < -80 or dewpoint_c > 50 do
       []
     else
       score_grid_point_with_data(hrrr_profile, valid_time, temp_c, dewpoint_c, derived)