Temperature for December
In Great Falls, MT during December the average high temperature is 36.7°F. The hottest day on record was December 28, 1980 when the temperature recorded was 63.0°F.

In Great Falls, MT during December the average high temperature is 36.7°F. The hottest day on record was December 28, 1980 when the temperature recorded was 63.0°F.
In December the average monthly rainfall in Great Falls, MT is 0.73 inches with rain usually falling on between 1 and 2 days. 1999 was the driest December with only 0.03 inches of rain falling, and 2006 was the wettest December with 3.44 inches of rain. The wettest single day in December was 29 December 2006 when 1.88 inches of rain fell.
In December it usually snows on between 9 and 9 days. In December there have been some years when thunderstorms have occurred, although there are other years when there hasn't been a thunderstorm in December.