Seattle, WA

Climate overview — based on NOAA 1991-2020 normals from SEATTLE BOEING FLD, WA US.

Csb Warm-summer Mediterranean climate 9a USDA hardiness Zone 9a

Year-round temperatures (°F)

30° 40° 50° 60° 70° 80° J F M A M J J A S O N D
Avg high Avg low

Climate summary

Seattle has an annual average temperature of 53.8°F with about 36.5 inches of precipitation per year. The warmest month is August (average high 77.4°F), and the coldest is December (average low 36.2°F). November is typically the wettest month (5.80 in) and July the driest (0.56 in).

Pleasant months
4 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
25.8°F
warmest to coldest month
Heating need
4,182
Cooling need
156

Best time to visit Seattle

Full guide →

Climate change signal

All-time records →

126 of 366 (34.4%) of Seattle's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.

1940s
18
1950s
68
1960s
48
1990s
4
2000s
69
2010s
98
2020s
61

Bars: number of all-time daily heat records still standing that were set in each decade.

Monthly averages

Month Avg High Avg Low Avg Temp Precipitation Snow Rainy days
January 48.6°F 36.8°F 42.7°F 5.21 in 19
February 50.7°F 36.8°F 43.7°F 3.71 in 16
March 54.8°F 39.4°F 47.1°F 3.94 in 18
April 59.8°F 43.6°F 51.7°F 2.89 in 15
May 66.5°F 49.3°F 57.9°F 1.98 in 11
June 71.2°F 54.0°F 62.6°F 1.22 in 9
July 77.3°F 57.5°F 67.4°F 0.56 in 3
August 77.4°F 58.1°F 67.8°F 0.83 in 4
September 71.7°F 53.9°F 62.8°F 1.37 in 9
October 61.0°F 46.4°F 53.7°F 3.49 in 15
November 53.0°F 39.9°F 46.4°F 5.80 in 18
December 47.8°F 36.2°F 42.0°F 5.49 in 18

Climate twins of Seattle

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

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