The temperatures in Washington DC in September are comfortable with low of 18°C and and high up to 27°C.
You can expect about 3 to 8 days of rain in Washington DC 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 DC in September 2025.
If you’re planning to visit Washington DC in the near future, we highly recommend that you review the 14 day weather forecast for Washington DC before you arrive.
Temperatures
27° / 18°
Rainy Days
5
Snowy Days
0
Dry Days
25
Rainfall
119
mm
Sun Hours
10.1
Hrs
