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.
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.
The warmest days on record are:
| 7 Aug 1983 | 104°F |
| 11 Aug 1984 | 104°F |
| 19 Jul 2007 | 104°F |
| 10 Jul 1973 | 102.9°F |
| 28 Jul 1975 | 102.9°F |
The warmest months on average were:
| July 2007 | 94.9°F |
| July 2003 | 93.8°F |
| July 2006 | 92°F |
| July 1985 | 91.8°F |
| July 2012 | 91.3°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 1989 | 0.1°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
The wettest days on record are:
| 27 June 1982 | 10.9 inches |
| 10 June 2006 | 2.1 inches |
| 3 June 2005 | 2 inches |
| 10 June 2002 | 1.8 inches |
| 12 June 1984 | 1.5 inches |
The wettest months on record are:
| February 1973 | 19.8 inches |
| March 1973 | 19.4 inches |
| August 1984 | 14.4 inches |
| June 1982 | 14.1 inches |
| January 1973 | 13.4 inches |
The driest months on record are:
| April 1996 | 0 inches |
| September 2012 | 0 inches |
| February 2005 | 0 inches |
| October 1987 | 0 inches |
| November 2001 | 0 inches |