August is one of the warmer months of the year in Washington, with average highs near 30.1°C and lows around 19.7°C (mean 24.9°C). It is about average for rainfall, averaging 100 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 Augusts in Washington were 2002 and 2016 — when the month averaged 26.9°C — while the coldest was 1992 at 22.5°C. Typical August days reach 30.1°C with nights near 19.7°C. The long-term trend is warming, about 0.3°C per decade.
August is about average for rainfall in Washington, averaging 100 mm of rainfall. The wettest August on record was 2020 with 244 mm, while the driest was 2025 at 25 mm.
Relative humidity in Washington during August averages 68%. The most humid August was 2003 at 84%, and the least humid was 2002 at 57%.
August receives about 5.3 kWh/m²/day of solar energy in Washington. The sunniest Augusts were 2016 and 2022 at 5.9 kWh/m²/day, and the cloudiest was 1989 at 4.6.
Average wind speed in Washington during August is 2 m/s. The windiest August was 2011 at 2.5 m/s, while the calmest were 1996 and 2003 at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 24.5°C | 24.4°C | 25.3°C | 25.0°C | 25.5°C | +1°C |
| Avg High | 30.0°C | 29.9°C | 30.3°C | 30.0°C | 30.6°C | +0.6°C |
| Avg Low | 19.1°C | 19.0°C | 20.2°C | 20.0°C | 20.4°C | +1.3°C |
| Avg Rain | 82 mm | 99 mm | 93 mm | 113 mm | 118 mm | +36 mm |
August temperatures in Washington have risen by about 1.5°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 9.2°C (1986) to a record high of 39.4°C (1983).
Rainfall in August is about average for rainfall, averaging 100 mm, with a wettest year of 244 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 30.1°C and nights around 19.7°C (mean 24.9°C) — warmer than Washington's yearly average — with higher rainfall (100 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 | 29.8°C | 24.2°C | 18.6°C | 35.9°C | 12.9°C | 25 mm | 61% | 2.1 m/s | 5.2 |
| 2024 | 30.9°C | 25.5°C | 20.1°C | 37.4°C | 12.9°C | 139 mm | 68% | 2.1 m/s | 5.4 |
| 2023 | 31.1°C | 25.7°C | 20.4°C | 35.0°C | 15.7°C | 62 mm | 64% | 2.3 m/s | 5.4 |
| 2022 | 31.9°C | 26.4°C | 20.9°C | 36.8°C | 16.6°C | 92 mm | 65% | 1.9 m/s | 5.9 |
| 2021 | 31.3°C | 26.5°C | 21.6°C | 36.5°C | 17.1°C | 146 mm | 71% | 1.8 m/s | 5.2 |
| 2020 🌧️ | 28.7°C | 24.8°C | 20.8°C | 34.3°C | 15.9°C | 244 mm | 81% | 2 m/s | 5.1 |
| 2019 | 31.6°C | 26.1°C | 20.6°C | 35.7°C | 16.0°C | 77 mm | 65% | 1.8 m/s | 5.6 |
| 2018 | 28.9°C | 24.8°C | 20.6°C | 32.4°C | 15.1°C | 140 mm | 81% | 1.9 m/s | 5.6 |
| 2017 | 28.0°C | 23.4°C | 18.9°C | 32.8°C | 14.8°C | 124 mm | 74% | 1.9 m/s | 5.5 |
| 2016 | 32.1°C | 26.9°C | 21.7°C | 36.7°C | 17.0°C | 75 mm | 68% | 2 m/s | 5.9 |
| 2015 | 30.8°C | 25.0°C | 19.1°C | 34.8°C | 15.6°C | 59 mm | 62% | 2 m/s | 5.7 |
| 2014 | 28.5°C | 23.4°C | 18.3°C | 32.3°C | 13.2°C | 121 mm | 72% | 1.9 m/s | 5.1 |
| 2013 | 28.3°C | 23.6°C | 19.0°C | 32.1°C | 13.5°C | 75 mm | 73% | 2 m/s | 4.9 |
| 2012 | 30.7°C | 25.9°C | 21.1°C | 35.0°C | 17.1°C | 105 mm | 68% | 1.9 m/s | 5.2 |
| 2011 | 30.3°C | 25.2°C | 20.1°C | 36.1°C | 14.6°C | 235 mm | 68% | 2.5 m/s | 5.4 |
| 2010 | 30.9°C | 25.8°C | 20.7°C | 36.9°C | 15.9°C | 116 mm | 68% | 2 m/s | 5.2 |
| 2009 | 30.2°C | 25.5°C | 20.8°C | 34.4°C | 15.8°C | 146 mm | 73% | 1.8 m/s | 5.3 |
| 2008 | 30.0°C | 24.3°C | 18.7°C | 33.9°C | 15.2°C | 44 mm | 63% | 2.1 m/s | 5.6 |
| 2007 | 32.2°C | 26.6°C | 21.0°C | 37.8°C | 17.0°C | 88 mm | 65% | 1.9 m/s | 5.2 |
| 2006 | 32.2°C | 26.5°C | 20.9°C | 37.4°C | 14.8°C | 30 mm | 62% | 2.1 m/s | 5.7 |
| 2005 | 31.7°C | 26.6°C | 21.4°C | 36.6°C | 16.2°C | 72 mm | 67% | 1.9 m/s | 5.2 |
| 2004 | 28.4°C | 23.6°C | 18.8°C | 32.9°C | 13.4°C | 109 mm | 76% | 2.1 m/s | 5.1 |
| 2003 | 28.0°C | 24.2°C | 20.3°C | 31.0°C | 13.8°C | 129 mm | 84% | 1.7 m/s | 5 |
| 2002 🔥 | 32.5°C | 26.9°C | 21.2°C | 37.8°C | 16.1°C | 79 mm | 57% | 2.2 m/s | 5.4 |
| 2001 | 30.7°C | 25.4°C | 20.1°C | 36.6°C | 16.8°C | 123 mm | 69% | 1.9 m/s | 5.5 |
| 2000 | 27.4°C | 22.9°C | 18.3°C | 31.8°C | 11.5°C | 109 mm | 74% | 2.3 m/s | 4.7 |
| 1999 | 31.0°C | 25.3°C | 19.7°C | 36.4°C | 14.6°C | 122 mm | 59% | 2.3 m/s | 5.3 |
| 1998 | 31.8°C | 25.8°C | 19.8°C | 36.5°C | 12.9°C | 56 mm | 61% | 2.2 m/s | 5.6 |
| 1997 | 29.9°C | 24.2°C | 18.6°C | 35.9°C | 13.9°C | 112 mm | 62% | 2.1 m/s | 5.3 |
| 1996 | 27.4°C | 22.8°C | 18.3°C | 31.4°C | 16.2°C | 96 mm | 77% | 1.7 m/s | 5.4 |
| 1995 | 32.2°C | 26.2°C | 20.2°C | 36.4°C | 15.8°C | 48 mm | 60% | 2.2 m/s | 5.5 |
| 1994 | 27.5°C | 22.6°C | 17.6°C | 32.4°C | 12.1°C | 132 mm | 76% | 2.1 m/s | 5.2 |
| 1993 | 31.2°C | 25.4°C | 19.7°C | 35.1°C | 14.8°C | 95 mm | 64% | 1.8 m/s | 5.4 |
| 1992 ❄️ | 27.7°C | 22.5°C | 17.3°C | 32.3°C | 12.5°C | 87 mm | 70% | 2.1 m/s | 5.2 |
| 1991 | 31.6°C | 25.8°C | 20.0°C | 37.4°C | 16.7°C | 76 mm | 63% | 2.1 m/s | 5.4 |
| 1990 | 28.3°C | 23.5°C | 18.8°C | 32.8°C | 16.0°C | 164 mm | 75% | 2 m/s | 4.8 |
| 1989 | 27.8°C | 23.3°C | 18.9°C | 32.0°C | 12.2°C | 51 mm | 78% | 2 m/s | 4.6 |
| 1988 | 32.1°C | 26.3°C | 20.5°C | 38.6°C | 14.0°C | 96 mm | 62% | 2.2 m/s | 5.4 |
| 1987 | 32.3°C | 26.3°C | 20.3°C | 36.7°C | 14.4°C | 41 mm | 57% | 2.3 m/s | 5.1 |
| 1986 | 29.2°C | 24.0°C | 18.8°C | 34.0°C | 9.2°C | 133 mm | 67% | 2.4 m/s | 5.2 |
| 1985 | 29.4°C | 24.2°C | 19.1°C | 37.2°C | 15.2°C | 101 mm | 66% | 2.1 m/s | 5 |
| 1984 | 27.9°C | 23.4°C | 19.0°C | 31.2°C | 11.9°C | 124 mm | 78% | 1.9 m/s | 5.5 |
| 1983 | 32.5°C | 26.3°C | 20.2°C | 39.4°C | 13.7°C | 66 mm | 61% | 2 m/s | — |
| 1982 | 29.2°C | 23.4°C | 17.7°C | 33.4°C | 9.6°C | 56 mm | 64% | 2.2 m/s | — |
| 1981 | 29.6°C | 23.7°C | 17.8°C | 32.9°C | 12.1°C | 71 mm | 63% | 2.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 30.1°C with lows near 19.7°C (mean 24.9°C), based on 45 years of NASA POWER data.
August averages 100 mm of rainfall in Washington, about average for rainfall. The wettest on record was 244 mm in 2020.
The hottest August reached 39.4°C in 1983. The coldest dipped to 9.2°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.5°C. Daytime highs moved from 29.7°C to 31°C and overnight lows from 18.8°C to 20.3°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 30.1°C daytime highs and 19.7°C at night.
Not quite — August is the 11th coolest month in Washington, averaging 24.9°C.
For August in Washington, pack light, breathable clothing and sun protection, with typical highs of 30.1°C and lows of 19.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 68% — moderately humid.
Average wind speed in August is 2 m/s. The windiest August on record averaged 2.5 m/s (2011).
The wettest August on record was 2020 with 244 mm. On average, August sees 100 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.
