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Multnomah County Climate

Multnomah County, Oregon

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec54.4°AVG °F

Avg Annual Temp

54.4°F

Annual Precip

49.1"

Annual Snowfall

5.4"

Extreme Heat Days

14

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
6.8"
5.1"
5.4"
4.0"
3.0"
2.1"
0.5"
0.6"
1.8"
4.5"
7.3"
7.9"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

9a

Minimum winter temperature range for plant survival

Growing Degree Days

2,662

Supports most vegetables & fruits

Last spring frost (32°F): 03/13
First fall frost (32°F): 11/22

Seasonal Overview

Comfort ZoneSpring48°59°12.4"Summer63°70°3.3"Fall47°65°13.7"Winter41°44°19.8"20°40°60°80°100°

National Comparison

Warmer than 49% of US counties
Wetter than 73% of US counties
More seasonal variation than 4% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Multnomah County

Climate Verdict

Multnomah County has a mild, with an average annual temperature of 54.4°F, moderately wet with 49.1 inches of annual precipitation, rare extreme heat with only 13.839999999999998 days above 90°F annually, light snow averaging 5.4 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are mild, with January temperatures averaging 41.2°F. summers are pleasantly cool with July averaging 69.2°F. The climate is remarkably stable year-round, with only a 28°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 Multnomah County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.

Regional Context

Multnomah County is 3.9°F warmer than the Oregon statewide average of 50.5°F, it is also noticeably wetter, receiving 11.7 inches more precipitation than the state average.

Climate Profile

About Multnomah County Weather

Temperately Topping the National Median

Multnomah County averages 54.4°F annually, making it slightly warmer than the national median. This marine-influenced climate pairs mild temperatures with a robust 49.1 inches of annual precipitation.

One of Oregon's Warmest Hubs

At 54.4°F, the county sits nearly four degrees above the Oregon state average of 50.5°F. It also receives about 12 inches more rain annually than the typical Oregon county.

Milder Winters Than the Interior

Compared to nearby Polk County's 50.1°F average, Multnomah remains notably warmer. Its 41.9°F winter average is significantly higher than eastern neighbors like Sherman County.

Wet Winters and Moderate Summer Heat

The county sees 14 days of extreme heat annually, with July temperatures averaging a comfortable 69.2°F. Most of the 49.1 inches of precipitation falls as rain, as the area only sees 5.4 inches of snow.

Gear Up for Rain and Humidity

High-quality rain gear is a daily necessity given the frequent precipitation. While extreme heat is less frequent than in the east, the 14 days above 90°F increasingly make portable AC units a wise investment.

Frequently Asked Questions

What is the average temperature in Multnomah County?
The average annual temperature in Multnomah County, OR is 54.4°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Multnomah County get?
Multnomah County receives an average of 49.1 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 Multnomah County?
Yes, Multnomah County receives an average of 5.4 inches of snowfall per year according to NOAA climate normals.
How hot does Multnomah County get in summer?
The average summer temperature (June-August) in Multnomah County is 67.3°F. The county experiences an average of 14 days per year above 90°F.
How cold are winters in Multnomah County?
The average winter temperature (December-February) in Multnomah County is 41.9°F. January, typically the coldest month, averages 41.2°F.

Track your own weather in Multnomah 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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