Great Falls, MT Climate

Summary Graph

The summary climate graph for Great Falls, MT shows a selection of temperature, rainfall and snow minimum, mean and maximum measures over the course of a year. Click on each of the measures in the key to toggle them on and off.

Graph of average and extreme temperature ranges by day for Great Falls, MT.


The warmest month in Great Falls International, Great Falls, Montana is July with an average high temperature of 85.7°F. The hottest day on record was August 7 1983 when the temperature hit 104.0°F. During January the overnight temperature drops to an average of 14.5°F with the lowest temperature of -42.0°F being recorded on December 25 1983.

Warmest Days

Warmest Months

Coldest Days

Coldest Months

The warmest days on record are:

7 Aug 1983104°F
11 Aug 1984104°F
19 Jul 2007104°F
10 Jul 1973102.9°F
28 Jul 1975102.9°F

The warmest months on average were:

July 200794.9°F
July 200393.8°F
July 200692°F
July 198591.8°F
July 201291.3°F

The coldest days on record are:

25 Dec 1983-42°F
4 Feb 1989-35°F
22 Dec 1990-35°F
8 Feb 1994-34.1°F
23 Jan 1982-32.1°F

The coldest months on average were:

December 1983-6.4°F
January 1982-4.4°F
January 1979-3.8°F
January 1978-0.1°F
February 19890.1°F


The wettest month by average rainfall in Great Falls, MT is June with an average of 2.7 inches of rain falling on 11 to 12 days.Although in May it typically rains on more days with 2.4 inches falling in 11 to 12 days. The driest month by average rainfall in Great Falls, MT is November with an average of 0.7 inches of rain falling on 2 to 3 days. Although in January it typically rains on less days with 1.0 inches falling in 1 to 1 days

Wettest Days

The wettest days on record are:

27 June 198210.9 inches
10 June 20062.1 inches
3 June 20052 inches
10 June 20021.8 inches
12 June 19841.5 inches

Wettest Months

The wettest months on record are:

February 197319.8 inches
March 197319.4 inches
August 198414.4 inches
June 198214.1 inches
January 197313.4 inches

Driest Months

The driest months on record are:

April 19960 inches
September 20120 inches
February 20050 inches
October 19870 inches
November 20010 inches