Boise, ID Climate

Summary Graph

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.

Graph of average and extreme temperature ranges by day for Boise, ID.


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.

Warmest Days

Warmest Months

Coldest Days

Coldest Months

The warmest days on record are:

28 Jul 1934111.2°F
24 Jul 1933110.3°F
14 Jul 2002109.9°F
7 Aug 1990109°F
21 Jul 1931108.3°F

The warmest months on average were:

July 2007100.1°F
July 201299.6°F
July 200699°F
July 200398.8°F
July 200296.9°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 19853.3°F
January 19375.7°F
January 19796.2°F
December 19906.7°F
January 198510.2°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

Wettest Days

The wettest days on record are:

11 May 19734.3 inches
29 May 19902 inches
1 May 19831.2 inches
23 May 20100.9 inches
26 May 19800.9 inches

Wettest Months

The wettest months on record are:

April 197331.7 inches
February 197315.6 inches
May 197311.7 inches
June 198210.5 inches
March 19738.6 inches

Driest Months

The driest months on record are:

January 19400 inches
March 19310 inches
April 19310 inches
May 19310 inches
June 19310 inches