Washington D.C., District of Columbia weather in September

Averages from 2021–2025 (150 days of record).

Average high: 79°F
Average low: 62°F
Rainy days: ~11 per month
Total precipitation: 4.6 in
Warmest recorded: 98°F
Coldest recorded: 49°F

Expect September days in Washington D.C., District of Columbia to top out around 79°F and cool to about 62°F overnight, with roughly 11 days of measurable rain across the month. In recent years September has ranged from 49°F to 98°F.

Other months

January February March April May June July August October November December

Current Washington D.C., District of Columbia forecast → · Historical data by Open-Meteo (ERA5).