weatherbycounty

Jerome County Climate

JanFebMarAprMayJunJulAugSepOctNovDec49.6°AVG °F

Avg Annual Temp

49.6°F

Annual Precip

10.4"

Annual Snowfall

Extreme Heat Days

43

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet
1.3"
0.8"
1.1"
1.0"
1.3"
0.6"
0.1"
0.3"
0.4"
0.9"
1.0"
1.5"
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

2,650

Supports most vegetables & fruits

Last spring frost (32°F): 05/02
First fall frost (32°F): 10/14

Seasonal Overview

Comfort ZoneSpring41°56°3.4"Summer65°74°1.1"Fall38°63°2.3"Winter29°33°3.6"20°40°60°80°100°

National Comparison

Warmer than 29% of US counties
Wetter than 2% of US counties
More seasonal variation than 62% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Jerome County

Climate Verdict

Jerome County has a cool, averaging 49.6°F annually, arid conditions receiving just 10.4 inches of precipitation annually, occasional hot days — 43.366666666666674 per year above 90°F. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 28.5°F. summers are warm — July averages 73.8°F. The 45°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

Growing season and gardening data is currently limited for Jerome County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.

Regional Context

Jerome County is 3.1°F warmer than the Idaho statewide average of 46.5°F, it is also noticeably drier, receiving 6.6 inches less precipitation than the state average.

Climate Profile

About Jerome County Weather

A warm pocket in the Intermountain West

Jerome County's 49.6°F average temperature is closer to the national median than many of its Idaho neighbors. The climate is distinctly arid, receiving only 10.4 inches of annual precipitation.

One of Idaho's warmer regions

The county is significantly warmer than the state average, topping 46.5°F by more than three degrees. It is also much drier, falling nearly 7 inches short of the Idaho average annual precipitation.

Warmer and drier than the North

Jerome is nearly 3 degrees warmer annually than Kootenai County and significantly drier than most northern Idaho regions. It shares a similar high-heat profile with neighboring Lincoln County.

High heat and dry winters

Summer is intense here, featuring 43 days of temperatures at or above 90°F and a July average of 73.8°F. While specific snowfall data is limited, the winter average sits at a relatively mild 30.0°F.

Prioritize cooling and water conservation

With 43 extreme heat days, efficient air conditioning is a primary necessity for Jerome County residents. Xeriscaping and water-wise landscaping are also recommended due to the low 10.4-inch annual rainfall.

Frequently Asked Questions

What is the average temperature in Jerome County?
The average annual temperature in Jerome County, ID is 49.6°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Jerome County get?
Jerome County receives an average of 10.4 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
How hot does Jerome County get in summer?
The average summer temperature (June-August) in Jerome County is 70.2°F. The county experiences an average of 43 days per year above 90°F.
How cold are winters in Jerome County?
The average winter temperature (December-February) in Jerome County is 30.0°F. January, typically the coldest month, averages 28.5°F.

Track your own weather in Jerome 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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