Washington DC in September
Summer heat fades
By Daan · Last reviewed October 2026
The short answer
September is one of the best months to visit Washington DC.
September cools down through the month, with warm days and calmer monuments.
September in detail
What September actually feels like
- Weather
- 18–27°C
- Warm, becoming comfortable.
- Crowds
- Moderate
- Prices
- $$$
- Mid-range rates.
+Warm days and fewer crowds.
–Early September can be humid.
My tip for September
Bike the National Mall in the late afternoon.
- Walking
- Museums
How September compares
Against the other eleven months
3rd of 12 overall in Washington DC, 3rd for weather, 5th for space, 6th for value. The emptiest month is January; the best value is January.
See all twelve months for Washington DCNot set on September?
Even stronger months in Washington DC
Also good in September
Weather
Weather in Washington DC in September
In September Washington DC averages a high of 27°C (81°F) and a low of 18°C (64°F), with about 100 mm of rain or snow over 9 wet days. The warmest month is July (around 32°C) and the coolest is January (around 7°C); the wettest month is July.
- Average high
- 27°C
- 81°F
- Average low
- 18°C
- 64°F
- Precipitation
- 100 mm
- Wet days
- 9
Climate data: NOAA (Ronald Reagan Washington National Airport, 1991–2020). Temperatures are averages of daily highs and lows.
Quick answers
Washington DC in September: the questions people ask
- Is September a good time to visit Washington DC?
- September is one of the best months to visit Washington DC. It ranks 3 of 12 months in Washington DC overall (3 for weather, 5 for space, 6 for value). The main upside: Warm days and fewer crowds. The main downside: Early September can be humid.
- What is the weather like in Washington DC in September?
- Average highs are around 27°C and lows around 18°C. Expect about 100 mm of rain or snow over roughly 9 wet days. Warm, becoming comfortable. For comparison, the warmest month is July (around 32°C) and the coolest is January (around 7°C).
- Is Washington DC crowded in September?
- Crowds are moderate. Moderate. The quietest month is January.
- How expensive is Washington DC in September?
- Prices are at level 3 of 5 ($$$). Mid-range rates. The best-value month is January.
- When is the best time to visit Washington DC?
- In the CrowdFreeViews month scores, October is the best month overall (September ranks 3 of 12). The quietest month is January and the best value is January.
Ready to book September in Washington DC?
Warm days and fewer crowds.
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