diff --git a/defaults/nginx.conf b/defaults/nginx.conf
index 5061a5d..8243079 100644
--- a/defaults/nginx.conf
+++ b/defaults/nginx.conf
@@ -40,12 +40,16 @@ http {
     }
 
     location ~* \.(js|css)$ {
-      expires modified 1h;
+      expires 1h;
     }
 
     location ~ ^/dwd/(icons|warn_icons)/ {
       root /home/weewx/public_html;
-      expires 1h;
+      expires 7d;
+    }
+
+    location ~ ^/dwd/[\w]+\.(gif|png) {
+      expires modified 1h;
     }
   }
 }