Skip to content
ZipNumbers

Ada County · Idaho

Boise, ID weather averages

NOAA climate normals for 1991-2020, measured at Boise Air Terminal, 6 km from the city centre — month by month temperature, rain and snow.

Quick answer

Boise averages a daily high of 63.6°F and a daily low of 41.3°F across the year, with 11.73 inches of precipitation. July is the warmest month at 91.2°F and December the coldest at 24°F.

Average annual high
63.6°FWarmest month July
Average annual low
41.3°FColdest month December
Precipitation per year
11.73 inWettest month December
Snowfall per year
19.2 in100.9 days at or below 32°F

Boise weather month by month

Normal daily high and low, precipitation and snowfall for each month, 1991-2020.

MonthHigh °FLow °FPrecip inSnow inRange
January37.824.71.245.124.7 to 37.8 degrees
February44.728.30.992.828.3 to 44.7 degrees
March54.634.41.391.334.4 to 54.6 degrees
April62.339.31.230.339.3 to 62.3 degrees
May71.646.51.39046.5 to 71.6 degrees
June81.353.70.69053.7 to 81.3 degrees
July91.260.40.33060.4 to 91.2 degrees
August89.759.60.24059.6 to 89.7 degrees
September78.8510.58051 to 78.8 degrees
October64.840.90.750.140.9 to 64.8 degrees
November48.231.91.352.631.9 to 48.2 degrees
December37.5241.55724 to 37.5 degrees

Source: NOAA NCEI, U.S. Climate Normals 1991-2020 — station USW00024131, Boise Air Terminal · rates as published for 1991-2020 normals

How to read Boise climate normals

What a climate normal is, and what it is not.

A normal is the average of thirty years of daily observations at one station — here Boise Air Terminal, 6 km from the centre of Boise. It describes a typical year, so any single year will run warmer, cooler, wetter or drier. Readings taken at an airport on the edge of town usually sit a degree or two below a dense downtown on summer nights. Boise sees about 47.5 days a year at or above 90°F and about 38.9 days with a tenth of an inch of precipitation or more.

Other Boise data on this site.