The temperatures in Washington in September are usually low and can range between 10°C and 17°C.
You can expect about 3 to 8 days of rain in Washington during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Washington in September 2025.
If you’re planning to visit Washington in the near future, we highly recommend that you review the 14 day weather forecast for Washington before you arrive.
Temperatures
17° / 10°
Rainy Days
5
Snowy Days
0
Dry Days
25
Rainfall
61
mm
Sun Hours
9.3
Hrs
