Washington, D.C. in September
In September, Washington, D.C. averages 26°C (79°F) during the day and 17°C (63°F) at night, with frequent rain — about 16 days of the month see precipitation (120 mm total).
Off-peakConditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.
It's peak hurricane season in Washington, D.C. during September. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.
How September compares to the rest of the year in Washington, D.C.
September is in the middle of the year for warmth in Washington, D.C. (4th of 12) and moderately rainy compared to the rest of the year (6th of 12). Daytime temperature runs 7°C above the annual average (19°C). September runs 3°C cooler than August (30°C) and cools 6°C in October (20°C).
September sunrise & sunset in Washington, D.C.
Times shown for Washington, D.C. local time (America/New_York), calculated for the 15th of September. They shift by a few minutes day to day across the month.
Photography light in Washington, D.C. — September
Golden-hour and blue-hour windows for the 15th of September, in Washington, D.C.'s local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — Washington, D.C. in September
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (Off-peak) and Washington, D.C.'s popularity.
Crowds & pricing — September in Washington, D.C.
This is off-peak for Washington, D.C. — the lowest prices of the year and the fewest crowds, but with real trade-offs: some restaurants, hotels, and beach businesses may close for the season; weather conditions can make outdoor activities unpredictable; and a handful of seasonal sights run reduced hours or close entirely. Great if you prefer a quiet local rhythm and don't mind the climate giving you reasons to choose indoor activities.
Why this tier: peak hazard season (1 active)
Sun & mosquito risk — September in Washington, D.C.
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
Washington, D.C. in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 6°C / 42°F | -3°C / 27°F | 77 mm | 14 | — |
| February | 9°C / 48°F | -1°C / 30°F | 92 mm | 14 | — |
| March | 13°C / 55°F | 2°C / 35°F | 87 mm | 15 | — |
| April | 19°C / 66°F | 8°C / 46°F | 100 mm | 16 | — |
| May | 24°C / 75°F | 13°C / 56°F | 122 mm | 18 | — |
| June | 29°C / 83°F | 18°C / 65°F | 131 mm | 19 | — |
| July | 31°C / 88°F | 21°C / 70°F | 165 mm | 21 | — |
| August | 30°C / 85°F | 20°C / 69°F | 150 mm | 20 | — |
| September | 26°C / 79°F | 17°C / 63°F | 120 mm | 16 | — |
| October | 20°C / 68°F | 11°C / 52°F | 96 mm | 15 | — |
| November | 13°C / 56°F | 4°C / 39°F | 86 mm | 11 | — |
| December | 9°C / 48°F | 1°C / 34°F | 105 mm | 12 | — |
Other cities with similar September weather
🌍 See the full ranked list of climate twins for Washington, D.C. in September →
Frequently asked questions
How hot is Washington, D.C. in September?
In September, Washington, D.C. averages a high of 26°C (79°F) and a low of 17°C (63°F) — generally warm.
Does it rain a lot in Washington, D.C. in September?
September is quite rainy in Washington, D.C., with about 16 rainy days on average.
Is September a good time to visit Washington, D.C.?
September is warm but on the rainy side. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for Washington, D.C. in September?
Pack light layers for warm days and cooler evenings, plus a compact umbrella or rain jacket. See the full September packing list for Washington, D.C. for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.