diff --git a/pyart/map/gates_to_grid.py b/pyart/map/gates_to_grid.py
index 93d72c4fc7..79e77f3422 100644
--- a/pyart/map/gates_to_grid.py
+++ b/pyart/map/gates_to_grid.py
@@ -72,6 +72,9 @@ def map_gates_to_grid(
     if isinstance(radars, Radar):
         radars = (radars, )
 
+    if len(radars) == 0:
+        raise ValueError('Length of radars tuple cannot be zero')
+
     skip_transform = False
     if len(radars) == 1 and grid_origin_alt is None and grid_origin is None:
         skip_transform = True
diff --git a/pyart/map/grid_mapper.py b/pyart/map/grid_mapper.py
index 1903681e53..191b8f6da4 100644
--- a/pyart/map/grid_mapper.py
+++ b/pyart/map/grid_mapper.py
@@ -77,6 +77,9 @@ def grid_from_radars(radars, grid_shape, grid_limits,
     if isinstance(radars, Radar):
         radars = (radars, )
 
+    if len(radars) == 0:
+        raise ValueError('Length of radars tuple cannot be zero')
+
     # map the radar(s) to a cartesian grid
     if gridding_algo == 'map_to_grid':
         grids = map_to_grid(radars, grid_shape, grid_limits, **kwargs)
@@ -396,6 +399,9 @@ def map_to_grid(radars, grid_shape, grid_limits, grid_origin=None,
     # make a tuple if passed a radar object as the first argument
     if isinstance(radars, Radar):
         radars = (radars, )
+        
+    if len(radars) == 0:
+        raise ValueError('Length of radars tuple cannot be zero')
 
     skip_transform = False
     if len(radars) == 1 and grid_origin_alt is None and grid_origin is None: