weatherbycounty

Lewis County Climate

JanFebMarAprMayJunJulAugSepOctNovDec46.8°AVG °F

Avg Annual Temp

46.8°F

Annual Precip

21.9"

Annual Snowfall

42.2"

Extreme Heat Days

24

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.9"
1.6"
2.3"
2.6"
2.8"
2.3"
0.9"
0.7"
1.0"
1.8"
2.2"
1.8"
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

1,800

Favors cool-season crops

Last spring frost (32°F): 05/23
First fall frost (32°F): 09/25

Seasonal Overview

Comfort ZoneSpring39°53°7.7"Summer59°66°3.9"Fall36°58°5.0"Winter29°34°5.3"20°40°60°80°100°

National Comparison

Warmer than 19% of US counties
Wetter than 17% of US counties
More seasonal variation than 19% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Lewis County

Climate Verdict

Lewis County has a cool, averaging 46.8°F annually, semi-arid conditions with only 21.9 inches of annual precipitation, occasional hot days — 23.933333333333334 per year above 90°F, moderate snowfall of 42.2 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 30.1°F. summers are pleasantly cool with July averaging 66.2°F. The 36°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and August the warmest.

Outdoor & Gardening Guidance

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

Regional Context

Lewis County closely matches the Idaho statewide average temperature of 46.5°F, it is somewhat wetter than average for Idaho.

Climate Profile

About Lewis County Weather

A snowy, moderate northern climate

Lewis County averages 46.8°F, which is slightly cooler than the national median but mild for the Idaho panhandle. It receives 21.9 inches of annual precipitation, making it moderately wet.

Just above the Idaho state average

At 46.8°F, Lewis County is slightly warmer than the Idaho statewide average of 46.5°F. Its 21.9 inches of precipitation sits about 5 inches higher than the state average of 17.0 inches.

Warmer and wetter than Jefferson

Lewis County is two degrees warmer and twice as wet as Jefferson County. It also sees double the snowfall of Jefferson, with 42.2 inches compared to 20.4 inches.

High snowfall and consistent heat

The county averages 42.2 inches of snow per year, with January temperatures hovering around 30.1°F. Summers bring a July average of 66.2°F and 24 days of temperatures hitting 90°F or higher.

Manage moisture and winter snow

With over 40 inches of snow, residents need effective plowing solutions and sturdy roofing. The combination of 21.9 inches of rain and moderate summer heat makes moisture-resistant building materials a wise investment.

Frequently Asked Questions

What is the average temperature in Lewis County?
The average annual temperature in Lewis County, ID is 46.8°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Lewis County get?
Lewis County receives an average of 21.9 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 Lewis County?
Yes, Lewis County receives an average of 42.2 inches of snowfall per year according to NOAA climate normals.
How hot does Lewis County get in summer?
The average summer temperature (June-August) in Lewis County is 63.7°F. The county experiences an average of 24 days per year above 90°F.
How cold are winters in Lewis County?
The average winter temperature (December-February) in Lewis County is 31.0°F. January, typically the coldest month, averages 30.1°F.

Track your own weather in Lewis 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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