August is one of the warmer months of the year in Washington, with average highs near 29°C and lows around 16°C (mean 22.5°C). It is about average for rainfall, averaging 86 mm of rainfall and 68% relative humidity across the period.
August is one of the warmer months of the year in Washington. Across 45 years of records, the warmest August in Washington was 2016 — when the month averaged 25.1°C — while the coldest was 1992 at 19.9°C. Typical August days reach 29°C with nights near 16°C. The long-term trend is warming, about 0.3°C per decade.
August is about average for rainfall in Washington, averaging 86 mm of rainfall. The wettest August on record was 1994 with 187 mm, while the driest was 2025 at 28 mm.
Relative humidity in Washington during August averages 68%. The most humid August was 1989 at 78%, and the least humid was 2002 at 60%.
August receives about 5.2 kWh/m²/day of solar energy in Washington. The sunniest Augusts were 2008, 2012 and 2025 at 5.8 kWh/m²/day, and the cloudiest was 1984 at 4.5.
Average wind speed in Washington during August is 0.1 m/s. The windiest Augusts were 2023, 2024 and 2025, among others at 0.1 m/s, while the calmest was 2018 at 0 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 22.1°C | 22.0°C | 22.7°C | 22.7°C | 23.3°C | +1.2°C |
| Avg High | 28.7°C | 28.6°C | 29.1°C | 29.1°C | 29.8°C | +1.1°C |
| Avg Low | 15.5°C | 15.4°C | 16.4°C | 16.3°C | 16.8°C | +1.3°C |
| Avg Rain | 87 mm | 87 mm | 89 mm | 77 mm | 89 mm | +2 mm |
August temperatures in Washington have risen by about 1.2°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 3.9°C (1982) to a record high of 37.5°C (1988).
Rainfall in August is about average for rainfall, averaging 86 mm, with a wettest year of 187 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
One of the best times to visit Washington
August is one of the best times to visit Washington. Expect days averaging 29°C and nights around 16°C (mean 22.5°C) — warmer than Washington's yearly average — with higher rainfall (86 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 29.7°C | 22.5°C | 15.3°C | 35.3°C | 7.8°C | 28 mm | 61% | 0.1 m/s | 5.8 |
| 2024 | 30.5°C | 23.7°C | 16.8°C | 36.6°C | 9.2°C | 73 mm | 65% | 0.1 m/s | 5.2 |
| 2023 | 28.7°C | 22.3°C | 16.0°C | 32.7°C | 11.0°C | 126 mm | 71% | 0.1 m/s | 5.1 |
| 2022 | 29.1°C | 23.0°C | 16.9°C | 33.9°C | 11.1°C | 107 mm | 73% | 0.1 m/s | 5.1 |
| 2021 | 30.4°C | 24.4°C | 18.5°C | 35.0°C | 12.6°C | 120 mm | 70% | 0.1 m/s | 5 |
| 2020 | 30.3°C | 23.8°C | 17.4°C | 34.4°C | 11.3°C | 81 mm | 66% | 0.1 m/s | 5.4 |
| 2019 | 29.7°C | 23.2°C | 16.7°C | 33.8°C | 10.8°C | 57 mm | 67% | 0.1 m/s | 5.6 |
| 2018 | 29.2°C | 23.4°C | 17.7°C | 33.0°C | 10.8°C | 120 mm | 76% | 0 m/s | 5 |
| 2017 | 27.0°C | 21.0°C | 15.0°C | 31.6°C | 9.6°C | 61 mm | 72% | 0.1 m/s | 5.4 |
| 2016 🔥 | 31.2°C | 25.1°C | 19.0°C | 35.5°C | 14.6°C | 69 mm | 68% | 0.1 m/s | 5.4 |
| 2015 | 29.7°C | 22.6°C | 15.4°C | 34.3°C | 11.9°C | 39 mm | 61% | 0.1 m/s | 5.7 |
| 2014 | 28.0°C | 21.5°C | 15.0°C | 31.9°C | 8.3°C | 101 mm | 70% | 0.1 m/s | 5.5 |
| 2013 | 27.0°C | 21.0°C | 15.0°C | 30.2°C | 8.1°C | 104 mm | 75% | 0.1 m/s | 5.3 |
| 2012 | 29.6°C | 22.6°C | 15.6°C | 34.4°C | 11.6°C | 59 mm | 65% | 0.1 m/s | 5.8 |
| 2011 | 28.6°C | 22.5°C | 16.4°C | 32.0°C | 10.1°C | 102 mm | 70% | 0.1 m/s | 5.4 |
| 2010 | 31.1°C | 24.4°C | 17.6°C | 35.0°C | 10.7°C | 60 mm | 63% | 0.1 m/s | 5.5 |
| 2009 | 28.2°C | 22.4°C | 16.6°C | 33.6°C | 8.5°C | 73 mm | 74% | 0.1 m/s | 5.2 |
| 2008 | 27.5°C | 20.8°C | 14.2°C | 32.2°C | 11.0°C | 47 mm | 68% | 0.1 m/s | 5.8 |
| 2007 | 28.6°C | 23.0°C | 17.4°C | 34.1°C | 11.3°C | 172 mm | 76% | 0.1 m/s | 5.1 |
| 2006 | 30.8°C | 23.9°C | 17.0°C | 35.7°C | 10.0°C | 55 mm | 62% | 0.1 m/s | 5.5 |
| 2005 | 30.8°C | 24.4°C | 18.0°C | 36.3°C | 11.4°C | 80 mm | 65% | 0.1 m/s | 4.9 |
| 2004 | 26.5°C | 20.7°C | 14.8°C | 30.8°C | 9.4°C | 112 mm | 76% | 0.1 m/s | 5 |
| 2003 | 29.1°C | 23.2°C | 17.4°C | 33.1°C | 11.4°C | 111 mm | 76% | 0.1 m/s | 5 |
| 2002 | 31.3°C | 24.1°C | 16.9°C | 37.0°C | 10.3°C | 58 mm | 60% | 0.1 m/s | 5.6 |
| 2001 | 30.5°C | 23.7°C | 16.9°C | 35.5°C | 11.6°C | 91 mm | 65% | 0.1 m/s | 5.1 |
| 2000 | 27.3°C | 21.2°C | 15.1°C | 31.0°C | 8.6°C | 87 mm | 71% | 0.1 m/s | 4.9 |
| 1999 | 29.1°C | 21.9°C | 14.8°C | 34.7°C | 8.3°C | 52 mm | 61% | 0.1 m/s | 5.2 |
| 1998 | 30.2°C | 23.0°C | 15.8°C | 33.8°C | 8.9°C | 88 mm | 64% | 0.1 m/s | 5.5 |
| 1997 | 27.3°C | 21.1°C | 14.9°C | 31.9°C | 9.8°C | 122 mm | 70% | 0.1 m/s | 4.8 |
| 1996 | 27.2°C | 21.0°C | 14.8°C | 31.0°C | 11.0°C | 62 mm | 74% | 0.1 m/s | 5.4 |
| 1995 | 31.8°C | 25.0°C | 18.1°C | 36.2°C | 12.7°C | 76 mm | 64% | 0.1 m/s | 5.5 |
| 1994 🌧️ | 25.9°C | 20.0°C | 14.1°C | 31.4°C | 6.5°C | 187 mm | 77% | 0.1 m/s | 4.8 |
| 1993 | 30.9°C | 23.8°C | 16.6°C | 36.0°C | 12.0°C | 53 mm | 61% | 0.1 m/s | 5.2 |
| 1992 ❄️ | 26.2°C | 19.9°C | 13.6°C | 31.6°C | 8.8°C | 85 mm | 72% | 0.1 m/s | 5 |
| 1991 | 30.3°C | 23.3°C | 16.3°C | 35.7°C | 12.2°C | 62 mm | 61% | 0.1 m/s | 5.1 |
| 1990 | 27.5°C | 21.3°C | 15.1°C | 32.4°C | 10.1°C | 87 mm | 75% | 0.1 m/s | 4.7 |
| 1989 | 26.2°C | 20.8°C | 15.4°C | 29.6°C | 8.3°C | 71 mm | 78% | 0.1 m/s | 5 |
| 1988 | 31.3°C | 24.3°C | 17.2°C | 37.5°C | 9.0°C | 96 mm | 61% | 0.1 m/s | 5.1 |
| 1987 | 29.7°C | 22.9°C | 16.1°C | 34.8°C | 8.6°C | 138 mm | 65% | 0.1 m/s | 4.6 |
| 1986 | 27.4°C | 20.9°C | 14.4°C | 31.4°C | 5.3°C | 67 mm | 66% | 0.1 m/s | 5 |
| 1985 | 27.9°C | 21.5°C | 15.2°C | 34.5°C | 10.7°C | 77 mm | 68% | 0.1 m/s | 4.6 |
| 1984 | 28.4°C | 22.3°C | 16.2°C | 31.9°C | 8.6°C | 118 mm | 74% | 0.1 m/s | 4.5 |
| 1983 | 31.3°C | 24.2°C | 17.0°C | 36.4°C | 10.2°C | 75 mm | 63% | 0.1 m/s | — |
| 1982 | 27.9°C | 20.8°C | 13.8°C | 34.3°C | 3.9°C | 84 mm | 63% | 0.1 m/s | — |
| 1981 | 28.1°C | 21.2°C | 14.2°C | 32.3°C | 7.0°C | 62 mm | 65% | 0.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 29°C with lows near 16°C (mean 22.5°C), based on 45 years of NASA POWER data.
August averages 86 mm of rainfall in Washington, about average for rainfall. The wettest on record was 187 mm in 1994.
The hottest August reached 37.5°C in 1988. The coldest dipped to 3.9°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.2°C. Daytime highs moved from 28.7°C to 29.7°C and overnight lows from 15.3°C to 16.7°C over the same span.
August is one of the warmer months of the year in Washington and about average for rainfall, so plan for around 29°C daytime highs and 16°C at night.
Not quite — August is the 11th coolest month in Washington, averaging 22.5°C.
For August in Washington, pack light layers you can adjust through the day, with typical highs of 29°C and lows of 16°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 68% — moderately humid.
Average wind speed in August is 0.1 m/s. The windiest August on record averaged 0.1 m/s (1981).
The wettest August on record was 1994 with 187 mm. On average, August sees 86 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Washington behaves each August, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for August specifically, along with year-by-year records and how the month has changed over the decades.
