Climate averages 1991–2020
Washington weather
in August.
A hot, moderately wet month: the 2nd warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Washington: daytime highs average 29.8°C and nights cool to about 20.6°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 89 mm of rain on roughly 10 days, which makes August a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 41 min on an average August day.
The nearest other city in this atlas is Arlington (Virginia), United States (6 km away). In August its highs average 29.3°C, 0.5°C cooler than Washington, with 89 mm of rain.
Among the 498 cities listed in the United States, Washington ranks joint 253rd of 498 for the warmest August highs and joint 317th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Washington is 0.1°C cooler than that mean.
From August to September, average highs fall by 3.9°C to 26.0°C, and monthly rainfall rises from 89 mm to 110 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Washington climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 6.0°C-2.3°C | -2.3°C | 78 | 8.6 | 9.810 h |
| February | 7.9°C-1.7°C | -1.7°C | 74 | 8.5 | 10.711 h |
| March | 12.5°C2.0°C | 2.0°C | 99 | 10.3 | 11.912 h |
| April | 18.8°C7.7°C | 7.7°C | 86 | 10.1 | 13.213 h |
| May | 23.7°C13.3°C | 13.3°C | 95 | 11.0 | 14.314 h |
| June | 28.5°C18.5°C | 18.5°C | 90 | 11.2 | 14.815 h |
| July | 31.1°C21.4°C | 21.4°C | 103 | 12.1 | 14.615 h |
| August, selected | 29.8°C20.6°C | 20.6°C | 89 | 10.1 | 13.714 h |
| September | 26.0°C17.0°C | 17.0°C | 110 | 9.2 | 12.512 h |
| October | 19.7°C10.4°C | 10.4°C | 86 | 7.8 | 11.211 h |
| November | 13.4°C4.5°C | 4.5°C | 74 | 7.5 | 10.110 h |
| December | 8.2°C0.1°C | 0.1°C | 90 | 8.8 | 9.59 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Arlington (Virginia), United States in AugustUnited States · 6 kmHigh 29.3°C · Low 20.1°C · 89 mm rain
- Alexandria, United States in AugustUnited States · 10 kmHigh 29.5°C · Low 20.7°C · 89 mm rain
- Silver Spring in AugustUnited States · 11 kmHigh 29.1°C · Low 20.1°C · 89 mm rain
- Centreville in AugustUnited States · 35 kmHigh 29.3°C · Low 20.4°C · 84 mm rain
- Germantown in AugustUnited States · 37 kmHigh 29.0°C · Low 19.6°C · 85 mm rain
- Columbia (Maryland), United States in AugustUnited States · 42 kmHigh 28.4°C · Low 20.2°C · 95 mm rain
- Baltimore in AugustUnited States · 57 kmHigh 28.6°C · Low 20.2°C · 93 mm rain
- Richmond in AugustUnited States · 154 kmHigh 29.9°C · Low 20.6°C · 109 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Washington) is explained once on the Washington year overview and on the Sources, method and limits page.
Arlington (Virginia), United States and Silver Spring lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.