diff --git a/modules/util/viirs.py b/modules/util/viirs.py
index d626df4936b584cfdba046940a461de7c26d1b27..7efb72c11cada1a51da0effec83bd093d8862196 100644
--- a/modules/util/viirs.py
+++ b/modules/util/viirs.py
@@ -30,6 +30,9 @@ def run_all(directory):
                 print(mfile)
                 run(mfile, ifile, mod_tiles, img_tiles)
 
+        if len(mod_tiles) == 0:
+            continue
+
         mod_nda = np.stack(mod_tiles)
         img_nda = np.stack(img_tiles)