The Weather Network
Weather
Maps
News
Video
|
Welcome
Monthly
⋮
Current
Hourly
7 Days
14 Days
Weekend
Monthly
Precipitation
Temperature
Wind
Temperature Unit Selection
°Celsius
°Fahrenheit
Monthly Historical Averages
Seattle-Tacoma International Air, WA
Content continues below
September
Average Temperature
High
20°
Feels 20
Low
12°
Feels 11
Average Precipitation
9 Days
Rain amount
50.3mm
Snow amount
0cm
Content continues below
Daily Historical Averages
September 2026
S
M
T
W
T
F
S
1
2
17°
3
17°
4
18°
5
19°
6
21°
7
20°
8
20°
9
22°
10
23°
11
21°
12
20°
13
20°
14
20°
15
21°
16
21°
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Forecast
Wednesday, September 2, 2026
Day
17°
Feels 16
Wind
22 km/h S
Gust
33 km/h
Humidity
68%
P.O.P
90%
Rain
~10 mm
Night
11°
Feels 10
Wind
17 km/h S
Gust
24 km/h
Humidity
94%
P.O.P
70%
Rain
~1 mm
Historical Averages
Sep 2
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity
Historical Averages are based on data recorded from 2000 onwards.