Great Falls, MT Climate in September

Temperature for September

In Great Falls, MT during September the average high temperature is 73.9°F. The hottest day on record was September 9, 1979 when the temperature hit 98.1°F.

Great Falls, MT daily average and extreme temperature range for September

Low Temperature

During September the overnight temperature drops to an average of 42.9°F, with the lowest temperature of 16.0°F being recorded on September 23, 2000. Overnight temperatures drop below freezing between 1 and 11 times in September.

Precipitation for September

In September the average monthly rainfall in Great Falls, MT is 1.36 inches with rain usually falling on between 6 and 7 days. 2012 was the driest September with only 0.00 inches of rain falling, and 1985 was the wettest September with 3.48 inches of rain. The wettest single day in September was 12 September 1978 when 1.65 inches of rain fell.

In September it usually snows on between 1 and 2 days. There are thunderstorms on between 1 and 2 days in September.