Casper, WY Climate in September

Temperature for September

In Casper, WY during September the average high temperature is 76.9°F. The hottest day on record was September 5, 1998 when the temperature hit 96.1°F.

Casper, WY daily average and extreme temperature range for September

Low Temperature

During September the overnight temperature drops to an average of 43.1°F, with the lowest temperature of 16.0°F being recorded on September 20, 1983. On average there are 1 days in September when the temperature stays below freezing all day. Overnight temperatures drop below freezing between 1 and 11 times in September.

Precipitation for September

In September the average monthly rainfall in Casper, WY is 0.88 inches with rain usually falling on between 7 and 8 days. 1941 was the driest September with only 0.00 inches of rain falling, and 1989 was the wettest September with 3.24 inches of rain. The wettest single day in September was 2 September 1973 when 1.93 inches of rain fell.

In September it usually snows on between 1 and 2 days. There are thunderstorms on between 2 and 3 days in September.