Boise weather by month
Average highs run from 39°F in January to 93°F in July, and January nights average 26°F. It gets 12 inches of rain and melted snow a year and 18 inches of snow. Expect about 55 days a year at 90°F or hotter. Nights drop below freezing about 108 times a year. The most comfortable months are May to June and September.
Best time to visit Boise
For comfortable weather, go in May to June and September. In those months the average high stays between 62°F and 86°F, nights average 42°F or warmer, and rain stays under 4.5 inches for the month.
Month by month
| Month | High | Low | Precip. | Snow | Wet days | Days 90°F+ | Nights below 32°F | Feels |
|---|---|---|---|---|---|---|---|---|
| January | 39°F | 26°F | 1.4 in | 5.3 in | 5 | 0 | 26 | cold |
| February | 46°F | 29°F | 1.0 in | 3.3 in | 4 | 0 | 20 | cold |
| March | 56°F | 35°F | 1.3 in | 1.2 in | 5 | 0 | 11 | cool |
| April | 62°F | 40°F | 1.2 in | 0.1 in | 4 | 0 | 5 | mild days, chilly nights |
| May | 72°F | 48°F | 1.5 in | 0.0 in | 4 | 1 | 1 | mild |
| June | 81°F | 54°F | 0.8 in | 0.0 in | 2 | 7 | 0 | warm |
| July | 93°F | 62°F | 0.2 in | 0.0 in | 1 | 22 | 0 | hot |
| August | 91°F | 61°F | 0.2 in | 0.0 in | 0 | 20 | 0 | hot |
| September | 80°F | 53°F | 0.4 in | 0.0 in | 1 | 5 | 0 | warm |
| October | 65°F | 42°F | 0.8 in | 0.1 in | 2 | 0 | 4 | mild days, chilly nights |
| November | 49°F | 32°F | 1.2 in | 2.0 in | 4 | 0 | 16 | cool |
| December | 39°F | 25°F | 1.5 in | 5.6 in | 5 | 0 | 25 | cold |
| Year | 64°F avg | 42°F avg | 11.5 in | 17.6 in | 38 | 55 | 108 |
"Wet days" are days with at least 0.1 inch of precipitation. "Feels" is a plain-language label for the average high. Normals for 1991-2020 from NOAA NCEI, station Boise Air Terminal, ID (USW00024131), 2.3 miles from the city center. Averages describe typical conditions, not a forecast.
Sunrise, sunset and daylight in Boise
The shortest day is December 21, with 8h 56m of daylight; the longest is June 21, with 15h 26m. The earliest sunset comes around December 6 (5:07 pm) and the latest around June 24 (9:30 pm). The sun sets after 8 pm on 174 days a year.
| On the 15th of | Sunrise | Sunset | Daylight |
|---|---|---|---|
| January | 8:15 am | 5:33 pm | 9h 19m |
| February | 7:43 am | 6:15 pm | 10h 32m |
| March | 7:56 am | 7:51 pm | 11h 54m |
| April | 7:02 am | 8:28 pm | 13h 26m |
| May | 6:20 am | 9:03 pm | 14h 43m |
| June | 6:03 am | 9:27 pm | 15h 25m |
| July | 6:17 am | 9:23 pm | 15h 06m |
| August | 6:50 am | 8:47 pm | 13h 58m |
| September | 7:24 am | 7:54 pm | 12h 30m |
| October | 7:59 am | 7:00 pm | 11h 01m |
| November | 7:39 am | 5:19 pm | 9h 40m |
| December | 8:11 am | 5:08 pm | 8h 57m |
Calculated for 2026 at the center of Boise with NOAA's solar equations, in local clock time (Mountain Time, including daylight saving time where it applies). Times shift by a minute or two from year to year.
Is Boise getting warmer?
The last 10 years averaged 1.6°F warmer than the 20th century. See the climate stripes for Boise.Frequently asked questions
What is the warmest month in Boise?
July is the warmest month, with an average high of 93°F and an average low of 62°F (NOAA 1991-2020 normals).
What is the coldest month in Boise?
December is the coldest, with average lows of 25°F and highs of 39°F.
What is the rainiest month in Boise?
December gets the most precipitation, 1.5 inches on average. August is the driest at 0.2 inches.
Does it snow in Boise?
Yes. Boise averages 18 inches of snow a year.
When is the best time to visit Boise?
For comfortable weather, May to June and September. Those months average highs between 62 and 86°F with lows of 42°F or more and modest rain.
Thinking of moving to Boise?
See what homes, rent and everyday prices cost, who lives there and how it compares with nearby cities on the full Boise profile.
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