Seattle September Weather

Averages and records for weather in Seattle, Washington in the month of September.
Typical Seattle September Weather
1991–2020
Average daily high 70.7 °F
Average daily low 53.1 °F
Average monthly precipitation 1.6 inches
Average monthly snow none
Daily chance of precipitation 27.8%
Daily chance of snow 0%
Seattle September Weather Records
1894–2024
Highest temperature 98 °F September 2, 1988
Lowest temperature 35 °F September 27, 1972
Highest daily low 69 °F September 2, 1974
Lowest daily high 49 °F September 26, 1948
Hottest average high temperature 76.4 °F 1967
Coldest average high temperature 62.8 °F 1914
Most daily precipitation 1.7 inches September 28, 2013
Most monthly precipitation 6.2 inches 2013
Most daily snow none -
Most monthly snow none -
Note: Daily averages are a moving average which includes 14 days before and after
Day Average (°F) Record (°F)
High Low High Low
September 1 74.2 55.3 91 46
September 2 73.9 55.1 98 41
September 3 73.6 55.0 92 45
September 4 73.3 54.9 88 42
September 5 73.1 54.8 88 44
September 6 72.8 54.6 90 43
September 7 72.6 54.5 94 45
September 8 72.4 54.4 86 42
September 9 72.2 54.2 89 40
September 10 72.0 54.1 92 39
September 11 71.7 53.9 93 40
September 12 71.4 53.7 87 44
September 13 71.2 53.5 87 39
September 14 71.1 53.4 93 42
September 15 70.9 53.2 93 42
September 16 70.6 53.1 91 44
September 17 70.3 52.9 85 42
September 18 69.9 52.6 85 41
September 19 69.5 52.5 86 40
September 20 69.2 52.3 88 40
September 21 68.9 52.0 88 36
September 22 68.6 51.8 92 37
September 23 68.3 51.7 85 40
September 24 67.9 51.5 89 38
September 25 67.5 51.3 85 36
September 26 67.0 51.0 82 39
September 27 66.6 50.8 89 35
September 28 66.2 50.6 86 38
September 29 65.9 50.3 81 37
September 30 65.6 50.1 82 36
Weather Station Details
Years Station Coordinates
1948–2024 Seattle Tacoma International Airport location
1894–1947 University of Washington location