diff --git a/worldengine/simulations/humidity.py b/worldengine/simulations/humidity.py
index 496aa384..a9586d79 100644
--- a/worldengine/simulations/humidity.py
+++ b/worldengine/simulations/humidity.py
@@ -1,5 +1,3 @@
-import numpy
-
 from worldengine.simulations.basic import find_threshold_f
 
 
@@ -18,7 +16,6 @@ def _calculate(world):
         humids = world.humids
         precipitationWeight = 1.0
         irrigationWeight = 3
-        data = numpy.zeros((world.height, world.width), dtype=float)
 
         data = (
             world.layers["precipitation"].data * precipitationWeight