September · United States
Best time to visit Washington DC in September Weather, crowds & prices
Weather in Washington DC in September
Average temperature 22°C, 98 mm of rain, about 15 days with 6+ hours of sunshine and 70% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
7.8/10
Ranked #5 of 12 months
- Avg temp
- 22°C
- Rainfall
- 98 mm
- Humidity
- 70%
- Days with 6h+ sun
- 15
- Crowd Density
- Moderate Crowds
- Average Expenses
- $$ · Moderate Cost ($$)
September in Washington DC scores 7.8/10 for sightseeing and cultural travel - an above-average month (#5 of 12). Expect around 22°C, 98 mm of rain, and roughly 15 days with 6+ hours of sunshine this month.
The National Mall lines up the Capitol, Smithsonian museums, and memorials within a walkable core.
September in Washington DC: strong conditions, 5th of 12
September averages 22°C (71°F) — pleasant for mornings and evenings on foot in the city, with a midday break when the sun is strongest.
Rainfall runs 98 mm, so plan one flexible day in three; you still get about 15 days with 6+ hours of sunshine and 12.2 hours of daylight.
It scores 7.8/10 here, 5th of 12 months, against 8.5/10 in the destination's best month.
Pack light clothing, a hat and real sun protection, a packable rain layer.
Figure on mid-season pricing, with crowds are moderate.
Frequently asked
- What is the weather like in Washington DC in September?
- In September, Washington DC averages 22°C, 98 mm of rain, and about 15 days with 6+ hours of sunshine. Its climate-comfort score is 7.8/10.
- Is September a good time to visit Washington DC?
- September earns a 7.8/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Washington DC in September?
- Expect about 98 mm of rain in September. Average humidity is 70% and there are about 15 days with 6+ hours of sunshine.
Curated in Washington DC
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Washington DC, United States. Live activities and tours from GetYourGuide, matched to this destination.