Weather on August 21
Costa Mesa, CA
55 Years of Data
Avg High
82°F
Avg Low
65°F
Warmest
1982
84°F avg
Coldest
1975
67°F avg
About This Date
August 21st in Costa Mesa, CA typically brings warm summer weather, with average highs around 82°F and lows near 65°F. Over 55 years of records, the warmest August 21st was in 1982 (84°F average), while the coldest was 1975 (67°F) — a 17°F range across recorded history. Rain or other precipitation has occurred on about 4% of August 21st dates historically. The last decade has been 2.7°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.7°F warmer on this date compared to 20-30 years ago.
Planning for August 21st in Costa Mesa, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 88° | 69° | 78° | — | — |
| 2024 | 85° | 67° | 76° | — | — |
| 2023 | 79° | 66° | 72° | 0.3" | — |
| 2022 | 78° | 71° | 75° | — | — |
| 2021 | 76° | 68° | 72° | 0.08" | — |
| 2020 | 87° | 74° | 80° | — | — |
| 2019 | 84° | 66° | 75° | — | — |
| 2018 | 82° | 71° | 77° | — | — |
| 2017 | 79° | 67° | 73° | — | — |
| 2016 | 80° | 65° | 72° | — | — |
| 2015 | 78° | 69° | 74° | — | — |
| 2014 | 81° | 70° | 75° | — | — |
| 2013 | 83° | 67° | 75° | — | — |
| 2012 | 81° | 71° | 76° | — | — |
| 2011 | 76° | 64° | 70° | — | — |
| 2010 | 82° | 64° | 73° | — | — |
| 2009 | 76° | 63° | 69° | — | — |
| 2008 | 76° | 64° | 70° | — | — |
| 2007 | 85° | 67° | 76° | — | — |
| 2006 | 79° | 64° | 71° | — | — |
| 2005 | 79° | 62° | 70° | — | — |
| 2004 | 75° | 65° | 70° | — | — |
| 2003 | 80° | 68° | 74° | — | — |
| 2002 | 75° | 65° | 70° | — | — |
| 2001 | 73° | 65° | 69° | — | — |
| 2000 | 78° | 65° | 71° | — | — |
| 1999 | 77° | 62° | 70° | — | — |
| 1998 | 90° | 63° | 76° | — | — |
| 1997 | 87° | 69° | 78° | — | — |
| 1996 | 87° | 62° | 75° | — | — |
| 1995 | 83° | 66° | 74° | — | — |
| 1994 | 81° | 65° | 73° | — | — |
| 1993 | 82° | 62° | 72° | — | — |
| 1992 | 88° | 65° | 76° | — | — |
| 1991 | 81° | 63° | 72° | — | — |
| 1990 | 81° | 61° | 71° | — | — |
| 1989 | 78° | 64° | 71° | — | — |
| 1988 | 77° | 59° | 68° | — | — |
| 1987 | 81° | 60° | 70° | — | — |
| 1986 | 90° | 68° | 79° | — | — |
| 1985 | 83° | 61° | 72° | — | — |
| 1984 | 85° | 71° | 78° | — | — |
| 1983 | 82° | 65° | 73° | — | — |
| 1982warmest | 98° | 69° | 84° | — | — |
| 1981 | 90° | 62° | 76° | — | — |
| 1980 | 83° | 60° | 71° | — | — |
| 1979 | 80° | 61° | 70° | — | — |
| 1978 | 81° | 60° | 70° | — | — |
| 1977 | 86° | 67° | 76° | — | — |
| 1976 | 82° | 60° | 71° | — | — |
| 1975coldest | 76° | 58° | 67° | — | — |
| 1974 | 79° | 63° | 71° | — | — |
| 1973 | 84° | 68° | 76° | — | — |
| 1972 | 94° | 61° | 77° | — | — |
| 1971 | 81° | 68° | 74° | — | — |
55 years of data from SANTA ANA JOHN WAYNE AP