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Boise County Climate

JanFebMarAprMayJunJulAugSepOctNovDec45.0°AVG °F

Avg Annual Temp

45.0°F

Annual Precip

25.3"

Annual Snowfall

93.1"

Extreme Heat Days

33

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.8"
2.5"
2.7"
2.1"
2.1"
1.4"
0.4"
0.5"
0.8"
1.8"
3.0"
4.3"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

6b

Minimum winter temperature range for plant survival

Growing Degree Days

1,692

Favors cool-season crops

Last spring frost (32°F): 06/06
First fall frost (32°F): 09/05

Seasonal Overview

Comfort ZoneSpring37°52°6.9"Summer59°67°2.2"Fall33°57°5.6"Winter25°29°10.6"20°40°60°80°100°

National Comparison

Warmer than 13% of US counties
Wetter than 21% of US counties
More seasonal variation than 44% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Boise County

Climate Verdict

Boise County has a cool, averaging 45.0°F annually, moderate rainfall of 25.3 inches per year, occasional hot days — 33.300000000000004 per year above 90°F, heavy winter snowfall averaging 93.1 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 25.2°F. summers are pleasantly cool with July averaging 66.8°F. The 42°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and July the warmest.

Outdoor & Gardening Guidance

Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.

Regional Context

Boise County closely matches the Idaho statewide average temperature of 46.5°F, it is also noticeably wetter, receiving 8.3 inches more precipitation than the state average.

Climate Profile

About Boise County Weather

High precipitation and cool temperatures

Boise County's 45.0°F average annual temperature is cooler than the national median. However, its 25.3 inches of annual precipitation is higher than many Western interior counties.

Slightly cooler and wetter than average

The county sits just below the Idaho average of 46.5°F but is much wetter than the state average of 17.0 inches. This results in heavy mountain snowpacks that feed the state's river systems.

The snow capital of the region

Boise County averages a massive 93.1 inches of snow, nearly triple that of neighboring Ada County. It also receives nearly twice the annual precipitation of its valley neighbors.

Extreme snowfall and moderate heat

The county is defined by its 93.1 inches of annual snow and a chilly January average of 25.2°F. Despite the snow, it still sees 33 days of heat over 90°F in the summer canyon depths.

Prepare for serious winter accumulation

Metal roofing and snow rakes are common needs for handling over 90 inches of annual snow. Residents should keep emergency supplies for potential winter road isolation when temperatures hit 26.6°F.

Frequently Asked Questions

What is the average temperature in Boise County?
The average annual temperature in Boise County, ID is 45.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Boise County get?
Boise County receives an average of 25.3 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Boise County?
Yes, Boise County receives an average of 93.1 inches of snowfall per year according to NOAA climate normals.
How hot does Boise County get in summer?
The average summer temperature (June-August) in Boise County is 63.7°F. The county experiences an average of 33 days per year above 90°F.
How cold are winters in Boise County?
The average winter temperature (December-February) in Boise County is 26.6°F. January, typically the coldest month, averages 25.2°F.

Track your own weather in Boise County

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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