Weather on August 21
Seattle, WA
55 Years of Data
Avg High
74°F
Avg Low
57°F
Warmest
2018
75°F avg
Coldest
1973
60°F avg
About This Date
August 21st in Seattle, WA typically brings pleasant summer weather, with average highs around 74°F and lows near 57°F. Over 54 years of records, the warmest August 21st was in 2018 (75°F average), while the coldest was 1973 (60°F) — a 15°F range across recorded history. Rain or other precipitation has occurred on about 20% of August 21st dates historically, with the wettest August 21st recording 1.73" of rain. The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.8°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Seattle, WA? Great weather for outdoor activities.
Warming Trend
0.8°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 76° | 57° | 66° | — | — |
| 2024 | 71° | 60° | 66° | — | — |
| 2023 | 76° | 54° | 65° | — | — |
| 2022 | 81° | 63° | 72° | — | — |
| 2021 | 70° | 56° | 63° | — | — |
| 2020 | 73° | 62° | 68° | — | — |
| 2019 | 71° | 60° | 66° | 0.25" | — |
| 2018warmest | 87° | 63° | 75° | — | — |
| 2017 | 81° | 57° | 69° | — | — |
| 2016 | 74° | 58° | 66° | — | — |
| 2015 | 75° | 61° | 68° | — | — |
| 2014 | 73° | 57° | 65° | — | — |
| 2013 | 80° | 58° | 69° | — | — |
| 2012 | 73° | 58° | 65° | — | — |
| 2011 | 87° | 60° | 74° | — | — |
| 2010 | 72° | 54° | 63° | 0.03" | — |
| 2009 | 70° | 60° | 65° | — | — |
| 2008 | 69° | 57° | 63° | — | — |
| 2007 | 73° | 61° | 67° | 0.08" | — |
| 2006 | 78° | 55° | 67° | — | — |
| 2005 | 76° | 56° | 66° | — | — |
| 2004 | 75° | 63° | 69° | 0.38" | — |
| 2003 | 84° | 59° | 72° | — | — |
| 2002 | 71° | 56° | 63° | — | — |
| 2001 | 66° | 57° | 62° | 1.14" | — |
| 2000 | 69° | 50° | 60° | — | — |
| 1999 | 74° | 60° | 67° | — | — |
| 1997 | 80° | 61° | 70° | — | — |
| 1996 | 75° | 52° | 63° | — | — |
| 1995 | 74° | 56° | 65° | — | — |
| 1994 | 73° | 61° | 67° | — | — |
| 1993 | 73° | 57° | 65° | — | — |
| 1992 | 73° | 54° | 63° | 0.05" | — |
| 1991 | 84° | 59° | 72° | — | — |
| 1990 | 68° | 63° | 65° | 0.36" | — |
| 1989 | 72° | 59° | 65° | 1.73" | — |
| 1988 | 73° | 51° | 62° | — | — |
| 1987 | 72° | 49° | 60° | — | — |
| 1986 | 86° | 56° | 71° | — | — |
| 1985 | 70° | 55° | 62° | — | — |
| 1984 | 80° | 54° | 67° | — | — |
| 1983 | 75° | 56° | 65° | — | — |
| 1982 | 79° | 58° | 68° | — | — |
| 1981 | 78° | 60° | 69° | — | — |
| 1980 | 68° | 52° | 60° | — | — |
| 1979 | 71° | 61° | 66° | 0.41" | — |
| 1978 | 72° | 58° | 65° | — | — |
| 1977 | 65° | 60° | 62° | — | — |
| 1976 | 69° | 55° | 62° | — | — |
| 1975 | 68° | 58° | 63° | — | — |
| 1974 | 72° | 57° | 64° | — | — |
| 1973coldest | 72° | 48° | 60° | — | — |
| 1972 | 70° | 57° | 63° | 0.53" | — |
| 1971 | 74° | 59° | 66° | 0.05" | — |
54 years of data from SEATTLE URBAN SITE