The summary climate graph for Boise, ID 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 Boise Air Terminal, Boise, Idaho is July with an average high temperature of 92.9°F. The hottest day on record was July 28 1934 when the temperature hit 111.2°F. During January the overnight temperature drops to an average of 22.7°F with the lowest temperature of -25.1°F being recorded on December 23 1990.
The warmest days on record are:
| 28 Jul 1934 | 111.2°F |
| 24 Jul 1933 | 110.3°F |
| 14 Jul 2002 | 109.9°F |
| 7 Aug 1990 | 109°F |
| 21 Jul 1931 | 108.3°F |
The warmest months on average were:
| July 2007 | 100.1°F |
| July 2012 | 99.6°F |
| July 2006 | 99°F |
| July 2003 | 98.8°F |
| July 2002 | 96.9°F |
The coldest days on record are:
| 23 Dec 1990 | -25.1°F |
| 21 Jan 1937 | -20.6°F |
| 23 Dec 1983 | -18°F |
| 6 Feb 1989 | -15°F |
| 9 Jan 1977 | -14.1°F |
The coldest months on average were:
| December 1985 | 3.3°F |
| January 1937 | 5.7°F |
| January 1979 | 6.2°F |
| December 1990 | 6.7°F |
| January 1985 | 10.2°F |
The wettest month by average rainfall in Boise, ID is April with an average of 1.7 inches of rain falling on 9 to 10 days.Although in March it typically rains on more days with 1.3 inches falling in 9 to 10 days. The driest month by average rainfall in Boise, ID is July with an average of 0.3 inches of rain falling on 3 to 4 days. Although in August it typically rains on less days with 0.4 inches falling in 3 to 4 days
The wettest days on record are:
| 11 May 1973 | 4.3 inches |
| 29 May 1990 | 2 inches |
| 1 May 1983 | 1.2 inches |
| 23 May 2010 | 0.9 inches |
| 26 May 1980 | 0.9 inches |
The wettest months on record are:
| April 1973 | 31.7 inches |
| February 1973 | 15.6 inches |
| May 1973 | 11.7 inches |
| June 1982 | 10.5 inches |
| March 1973 | 8.6 inches |
The driest months on record are:
| January 1940 | 0 inches |
| March 1931 | 0 inches |
| April 1931 | 0 inches |
| May 1931 | 0 inches |
| June 1931 | 0 inches |