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Snohomish County Climate

Snohomish County, Washington

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec50.6°AVG °F

Avg Annual Temp

50.6°F

Annual Precip

54.1"

Annual Snowfall

3.6"

Extreme Heat Days

5

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
7.2"
5.0"
5.7"
4.4"
3.4"
2.7"
1.2"
1.4"
2.7"
5.4"
8.0"
7.2"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

8b

Minimum winter temperature range for plant survival

Growing Degree Days

1,762

Favors cool-season crops

Last spring frost (32°F): 04/16
First fall frost (32°F): 10/25

Seasonal Overview

Comfort ZoneSpring44°55°13.4"Summer59°64°5.2"Fall43°59°16.2"Winter38°41°19.3"20°40°60°80°100°

National Comparison

Warmer than 32% of US counties
Wetter than 86% of US counties
More seasonal variation than 3% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Snohomish County

Climate Verdict

Snohomish County has a mild, with an average annual temperature of 50.6°F, moderately wet with 54.1 inches of annual precipitation, rare extreme heat with only 4.583333333333333 days above 90°F annually, light snow averaging 3.6 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 39.1°F. summers are pleasantly cool with July averaging 64.1°F. The climate is remarkably stable year-round, with only a 25°F difference between January and July. December is typically the coldest month and August the warmest.

Outdoor & Gardening Guidance

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

Regional Context

Snohomish County closely matches the Washington statewide average temperature of 49.9°F, it is also noticeably wetter, receiving 15.6 inches more precipitation than the state average.

Climate Profile

About Snohomish County Weather

Temperate and Consistently Moist

Snohomish County maintains an average annual temperature of 50.6°F, sitting just below the national median. With 54.1 inches of annual precipitation, the climate is characterized by frequent cloud cover and rain.

Slightly Warmer than the Washington Average

The 50.6°F annual average is slightly higher than the state's 49.9°F mean. Its 54.1 inches of rain puts it well above the state average of 38.5 inches, typical for the Puget Sound region.

Drier and Less Snowy than Pierce County

Snohomish County is significantly less snowy than Pierce County, receiving only 3.6 inches of snow compared to 38.3 inches. It also sees slightly less annual rainfall than its southern neighbor.

Mild Summers with Minimal Snowfall

July temperatures average 64.1°F with only 5 days of extreme heat above 90°F. Winters are mild but wet, with January averages around 39.1°F and very little frozen precipitation.

Focus on Reliable Rain Gear

With only 5 days of extreme heat, cooling is less critical than moisture management. Residents should prioritize high-quality rain shells and ensure home gutters are clear to handle the consistent annual rainfall.

Frequently Asked Questions

What is the average temperature in Snohomish County?
The average annual temperature in Snohomish County, WA is 50.6°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Snohomish County get?
Snohomish County receives an average of 54.1 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 Snohomish County?
Yes, Snohomish County receives an average of 3.6 inches of snowfall per year according to NOAA climate normals.
How hot does Snohomish County get in summer?
The average summer temperature (June-August) in Snohomish County is 62.6°F. The county experiences an average of 5 days per year above 90°F.
How cold are winters in Snohomish County?
The average winter temperature (December-February) in Snohomish County is 39.3°F. January, typically the coldest month, averages 39.1°F.

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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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