Seattle (WA) monthly weather averages

  • Average daytime temperature

    The bar chart below shows the average monthly peak daytime temperatures at Seattle

    Seattle average temperature chart
    Average monthly temperatures in Seattle (degrees centigrade and fahrenheit)
      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    °C 7.2 9.9 11.7 14.1 17.8 20.9 23.5 23.5 20.5 15.5 10.4 7.5
    °F 44.9 49.9 53 57.3 64 69.6 74.4 74.3 68.8 59.8 50.7 45.5

    Please note: these are the average peak daytime temperatures (usually around mid-afternoon) so do not show daytime / night highs and lows. To see the daily range of temperatures have a look at the temperature max / min chart below.

  • Average rainfall & rainy days

    The graph below shows the average rainfall and number of rainy days per month.

    Average monthly rainfall in Seattle (mm and inches)
      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    mm 149 105 95 66 46 41 21 31 49 87 150 151
    inches 5.9 4.1 3.7 2.6 1.8 1.6 0.8 1.2 1.9 3.4 5.9 5.9
    Rainy days 18 15 16 13 11 8 5 6 9 12 17 18
  • Average daily sunshine

    The bar chart below shows the average daily sunshine hours in Seattle

    Average daily sunshine Seattle
      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    Hrs sunshine 2.5 4.1 5.9 7.2 8.6 9.4 10.8 9.8 7.8 5 2.7 2
  • Day / night temperatures

    The graph below shows the daily range of temperatures for each month.

    Maximum and minimum daily temperatures in Seattle (degrees centigrade and fahrenheit)
      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    Min °C 1.7 2.9 3.6 5.1 8 11.1 12.8 13.1 10.9 7.6 4.5 2.4
    Max °C 7.3 10.1 11.9 14.3 18 21.2 23.8 23.8 20.7 15.7 10.6 7.7
    Min °F 35.1 37.2 38.4 41.2 46.4 51.9 55 55.5 51.6 45.6 40 36.2
    Max °F 40.1 43.7 45.9 49.5 55.4 61 64.9 65.1 60.4 52.9 45.5 41
  • Sea temperature

    The graph below shows the average sea temperature.

    Average sea temperature around Seattle in degrees centigrade and fahrenheit
      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    °C 8.1 8 8.3 9.1 10.5 12 13.1 13.4 12.8 11.2 9.7 8.6
    °F 46.5 46.4 47 48.4 50.9 53.6 55.5 56.2 55.1 52.1 49.5 47.5
  • Wind speed

    The graph below shows the average wind speed.

    Average wind speed in Seattle (mph and kmh)
      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    km/h 15 14 14 14 13 13 13 12 12 12 14 14
    mph 9 9 9 9 8 8 8 7 7 7 9 9

    A monthly average windspeed of over 16km/h or 10mph suggests a location is fairly windy.

  • Relative humidity

    The graph below shows the average relative humidity.

    Average relative humidity in Seattle
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    80% 77% 74% 71% 69% 67% 65% 68% 73% 79% 81% 81%
Seattle

Other monthly averages

Seattle weather stats

Seattle weather statistics
Hottest month: August 23.5°C 74.3°F
Driest month: July 21mm 0.8ins
Sunniest month: July 10.8hrs
Coldest month: January 7.2°C 45°F
Wettest month: December 151mm 5.9ins
Warmest sea: August 13.4°C 56.1°F
Map showing location of Seattle (47.60621, -122.33207)

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