Boise weather by month

Boise runs from an average daily high of 39°F in January to 93°F in July, with overnight lows between 25°F (December) and 62°F (July).

December is the wettest month (1.5 inches) and August the driest (0.2 inches); about 12 inches fall in a normal year.

Average highs reach 90°F or more in Jul-Aug.

Average lows are at or below freezing in Jan-Feb and Nov-Dec.

Snow is a real part of the year here: about 18 inches in a normal winter, most in December.

By a simple rule (average highs of 65-88°F, lows of 40°F or more and rain at or under the yearly average), the comfortable months for Boise day trips are Jun and Sep.

Month by month in Boise

Month	Average high	Average low	Rain (in)	Snow (in)	Day trips open
January	39°F	26°F	1.4	5.3	36 of 41
February	46°F	29°F	1.0	3.3	36 of 41
March	56°F	35°F	1.3	1.2	36 of 41
April	62°F	40°F	1.2	0.1	36 of 41
May	72°F	48°F	1.4	0.0	37 of 41
June best	81°F	54°F	0.8	0.0	40 of 41
July	93°F	62°F	0.2	0.0	41 of 41
August	91°F	61°F	0.2	0.0	41 of 41
September best	80°F	53°F	0.4	0.0	39 of 41
October	65°F	42°F	0.8	0.1	38 of 41
November	49°F	32°F	1.2	2.0	36 of 41
December	39°F	25°F	1.5	5.6	36 of 41

The numbers are from NOAA's station at Boise Air Terminal, Id (USW00024131). Climate normals 1991-2020: long-run averages, not a forecast. "Day trips open" counts the places within 3 hours that are open or in season on the 15th, from our own place data.

Questions about Boise weather

What is the best time to visit Boise?

By a simple rule (average highs of 65-88°F, lows of 40°F or more and rain at or under the yearly average), the comfortable months for Boise day trips are Jun and Sep.

What is the hottest and coldest month in Boise?

July is the hottest (average high 93°F) and December the coolest (average low 25°F).

When does it rain the most in Boise?

December is the wettest month (1.5 inches) and August the driest (0.2 inches).

Does it snow in Boise?

Yes: about 18 inches in a normal year, most in December.

Where do these weather numbers come from?

The numbers are from NOAA's station at Boise Air Terminal, Id (USW00024131). They are 1991-2020 climate normals (long-run averages), not a forecast. For today's weather use the National Weather Service forecast.