Washington (DC) weather in August

August in Washington: sweltering, rainy — fine if you can take 35°C afternoons.

Updated September 2026 · climate normals from ERA5 reanalysis

Washington🇺🇸 United States · Northeast & Atlantic Canada · City70
  1. 59Jan
  2. 63Feb
  3. 73Mar
  4. 83Apr
  5. 87May
  6. 78Jun
  7. 65Jul
  8. 70Aug
  9. 80Sep
  10. 85Oct
  11. 71Nov
  12. 58Dec

#8 of 12 months in Washington · #938 of 1413 destinations to visit in August · comfort 70/100 (tier B)

Days
31°C
Nights
21°C
Wet days
9
Sun
10.5 h
Humidity
74%
Daylight
14 h
Washington, United States
Photo: Mark Stebnicki · Pexels

Traveller notes on Washington in August

Other months in Washington

June here is hot and humid but not yet August, and regulars are precise about the pattern: mid to high eighties by day, sixties at night, and afternoon thunderstorms that come out of nowhere, rain hard for a few minutes and leave the air more humid than before. Our row gives 29.7C reading as 32C over 18.6C nights, with 107.1mm across 9.4 days, which is eleven millimetres a time. Their packing advice follows the humidity - loose natural fibres in light colours, because synthetics turn into plastic bags - and their warning is the opposite problem, that indoor air conditioning is usually set far too cold. The record: humidity 69 percent, 11.4 hours of sun and AQI 68.
NaturalFibresAndAShortStorm · June · 1 month ago · Read more on Tripadvisor ↗
Regulars time this city by the school calendar. Labour Day is the first Monday of September and ends the summer season; October brings the school groups back in force; the fortnight between is the quietest good weather of the year. The weather follows the same split - the first week is still summer, mid-80s with the humidity to match, and the drier air does not usually arrive until mid-to-late month. Our row averages 27.8C reading as 30C at 74 percent humidity with a 16.1C dew point, over 17.3C nights, and 108.4mm of rain across 8.1 days. Book the second half if you can. The record: 8.6 hours of sun and AQI 47.
AfterLabourDayBeforeTheSchoolTrips · September · 1 month ago · Read more on Tripadvisor ↗
Washington DC-forum threads on late May draw a before/after line at Memorial Day: earlier in the month runs fair and warm with just the odd afternoon thunderstorm, while posters note humidity climbs noticeably by late May and into June, ahead of July and August's muggier stretch. The record backs the thunderstorm read more than the 'dry spring' reputation: 137mm of rain across more than twelve days, the wettest month on this destination's calendar, alongside 24.6C days, 13.4C nights and 9.3 hours of sun. Good jacket-optional weather, but pack for rain more than forum nostalgia about 'before the humidity' suggests.
TidalBasinLateMay · May · 1 month ago · Read more on Tripadvisor ↗
Washington DC forum threads describe January as genuinely the coldest month, with average highs in the low 40s Fahrenheit and lows in the mid-20s, plus real wind chill that makes it feel colder still. A typical winter brings around 6 inches of snow total for the month in smaller spurts rather than one big dump, though posters noted an occasional major coastal storm can bring far more at once - DC still gets meaningfully less snow than cities like Boston given its more southern, coastal-influenced position. The consistent packing advice: several thinner warm layers under a proper coat work better than one very thick jacket, plus wool accessories that handle wet weather better than cotton.
NationalMallRegular · January · 1 month ago · Read more on Tripadvisor ↗

Year-round notes are on Washington's overview. Add your own note from Washington's card on the map.

Washington climate normals — August

Daytime high31°C / 89°F🔥 sweltering
Nighttime low21°C / 70°F
Feels like (high)35°C / 95°F
Rainfall122 mm / 4.8 in🌧 rainy
Rainy days9 days
Humidity74%💧 humid
Dew point19°C / 66°F
Sunshine10.5 h/day
Daylight13.6 h
Wind12 km/h / 7 mph
Air quality (US AQI)64🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Washington in August

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

BusySummer break in United States, school holidays in 2 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Washington's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherWashington's best weather comes in April, May and October — separate windows, not one continuous season.

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Best weatherFair weatherToughest weather

What's on in Washington in August

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Rule

    Washington Monument timed tickets

    1 Jan – 31 DecBook early

    The lift to the top runs on timed tickets released online a month ahead, with a small same-day batch in the morning. The African American History museum works the same way in the busy months. Source ↗

  • Hazard

    Summer heat and humidity

    20 Jun – 5 Sep · usuallyExtreme heat

    The city was built on a river flat and the summer behaves accordingly, with afternoon thunderstorms and heat advisories through July and August. The monuments walk is best done at seven in the morning. Source ↗

  • Season

    August recess

    1 Aug – 5 SepOff-season shutdown

    Congress goes home, the lobbying and lawyer city empties with it, and downtown restaurants that live on expense accounts run their quiet weeks. Hotel rates fall while the museums stay open.

What's on around the world in August →

Nearby, and something's on

Within 300 km of Washington — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Washington?

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Washington in August — FAQ

Is August a good time to visit Washington?
August in Washington: sweltering, rainy — fine if you can take 35°C afternoons. It ranks #8 of 12 months for Washington on SeasonMap's comfort score (70/100).
What is the weather like in Washington in August?
In August, Washington averages a daily high of 31.4°C and a low of 21°C, with about 121.6 mm of rain over roughly 9.1 rainy days.
What is the air quality in Washington in August?
Washington has a mean US Air Quality Index of about 64 in August.

Within 300 km: Virginia Beach's East Coast Surfing Championships around 17–24 Aug, and Baltimore's Chesapeake blue crab season on 1 Apr – 30 Nov.