Climateby Month

Seattle, WA climate by month

NOAA 1991-2020 normals · 173 ft elevation · also covers Bellevue

Seattle has mild summers and chilly winters. Highs peak at 77°F in August and fall to 47°F in December. The wettest month is December (about 19 wet days) and the driest is July (about 5). Normal snowfall is about 3.8 in a year. By our comfort score the best months are June, July and August.

Warmest month
77°F
August normal high
Coldest month
37°F
February normal low
Wet days a year
163
37.8 in of precipitation
Snow a year
3.8 in
normal snowfall

How warm is Seattle?

Normal highs range from 47°F in December to 77°F in August.

30°40°50°60°70°80° January: normal high 47°F (8°C), low 37°F (3°C) 47° 37° February: normal high 50°F (10°C), low 37°F (3°C) March: normal high 54°F (12°C), low 39°F (4°C) April: normal high 59°F (15°C), low 43°F (6°C) May: normal high 65°F (18°C), low 48°F (9°C) June: normal high 70°F (21°C), low 53°F (12°C) July: normal high 77°F (25°C), low 57°F (14°C) 77° 57° August: normal high 77°F (25°C), low 57°F (14°C) September: normal high 71°F (22°C), low 53°F (12°C) October: normal high 61°F (16°C), low 47°F (8°C) November: normal high 52°F (11°C), low 41°F (5°C) December: normal high 47°F (8°C), low 37°F (3°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Seattle?

December has the most wet days (about 19); the year brings about 38 in of precipitation.

January: 19 wet days February: 16 wet days March: 18 wet days April: 16 wet days May: 12 wet days June: 11 wet days July: 5 wet days 5 August: 6 wet days September: 9 wet days October: 15 wet days November: 19 wet days December: 19 wet days 19 JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 3.8 in a year, most of it in December.

January: 0.9 in of snow February: 1.0 in of snow March: 0.0 in of snow 0.0 April: 0.0 in of snow May: 0.0 in of snow June: 0.0 in of snow July: 0.0 in of snow August: 0.0 in of snow September: 0.0 in of snow October: 0.0 in of snow November: 0.2 in of snow December: 1.7 in of snow 1.7 JFMAMJJASOND

How humid is Seattle?

Muggy days (dew point 65°F or higher) are rare in any month.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 0 muggy days July: 0 muggy days August: 0 muggy days September: 0 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Seattle-Tacoma International Airport, 11 mi S of the city center.

How much daylight?

Daylight ranges from about 8.5 hours in December to 15.9 hours in June.

January: 8.9 hours of daylight February: 10.3 hours of daylight March: 11.9 hours of daylight April: 13.7 hours of daylight May: 15.1 hours of daylight June: 15.9 hours of daylight 15.9 July: 15.5 hours of daylight August: 14.2 hours of daylight September: 12.6 hours of daylight October: 10.8 hours of daylight November: 9.3 hours of daylight December: 8.5 hours of daylight 8.5 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Seattle, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 47°F37°F 5.1 in19 0.9 in 0 8.9 h
February 50°F37°F 3.5 in16 1.0 in 0 10.3 h
March 54°F39°F 3.9 in18 0.0 in 0 11.9 h
April 59°F43°F 3.0 in16 0.0 in 0 13.7 h
May 65°F48°F 2.2 in12 0.0 in 0 15.1 h
June 70°F53°F 1.6 in11 0.0 in 0 15.9 h
July 77°F57°F 0.8 in5 0.0 in 0 15.5 h
August 77°F57°F 1.0 in6 0.0 in 0 14.2 h
September 71°F53°F 1.7 in9 0.0 in 0 12.6 h
October 61°F47°F 3.6 in15 0.0 in 0 10.8 h
November 52°F41°F 5.8 in19 0.2 in 0 9.3 h
December 47°F37°F 5.5 in19 1.7 in 0 8.5 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Seattle

By our comfort score, the best months are June, July and August.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 330124
Feb 39092
Mar 462110
Apr 56590
May 731460
Jun 852250
Jul 862221
Aug 832231
Sep 802350
Oct 52790
Nov 360121
Dec 330124

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Seattle

The last spring frost typically comes around Mar 8, and the first fall frost around Nov 23, leaving 259 frost-free days in a typical year.

Frost and freeze dates for Seattle
Typical date1 year in 10
Last spring frost (32°F)Mar 8after Mar 29
First fall frost (32°F)Nov 23before Nov 4
Last hard freeze (28°F)Feb 11after Mar 1
First hard freeze (28°F)Dec 11before Nov 17
Frost-free season259 daysunder 231 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Seattle Sand Pt WSFO (USW00094290), NOAA 1991-2020 freeze probabilities. Frost dates for every city in Washington.

Hottest and coldest readings, 1991-2020

The highest reading was 105°F (July 29, 2009); the lowest was 17°F (December 9, 2009).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Seattle

Similar climates elsewhere

Also covers

Bellevue uses the same temperature and rain stations as Seattle, so its monthly numbers are the ones on this page.

Where the numbers come from

  • Temperature, rain, snowfall, snow depth and frost dates: Seattle Sand Pt WSFO (USW00094290), 6.6 mi NNE of the city center, 60 ft (113 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Humidity and wind by hour: Seattle Boeing Fld (USW00024234), 5.4 mi SSE of the city center, 20 ft (153 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Seattle-Tacoma International Airport (727930-24233), 11 mi S of the city center, 369 ft (196 ft higher than the city). Hourly observations, 1991-2020.
  • Not available for this location: cloud cover (no station close enough or similar enough in elevation).

Distances from the city center (USGS). Methodology · Report an error