Weather on October 21
Costa Mesa, CA
55 Years of Data
Avg High
78°F
Avg Low
59°F
Warmest
1990
77°F avg
Coldest
2004
60°F avg
About This Date
October 21st in Costa Mesa, CA typically brings pleasant fall weather, with average highs around 78°F and lows near 59°F. Over 55 years of records, the warmest October 21st was in 1990 (77°F average), while the coldest was 2004 (60°F) — a 17°F range across recorded history. Rain or other precipitation has occurred on about 9% of October 21st dates historically. The last decade has been 4.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.0°F warmer on this date compared to 20-30 years ago.
Planning for October 21st in Costa Mesa, CA? Great weather for outdoor activities.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 78° | 59° | 69° | — | — |
| 2024 | 83° | 59° | 71° | — | — |
| 2023 | 81° | 64° | 72° | — | — |
| 2022 | 77° | 66° | 72° | — | — |
| 2021 | 76° | 54° | 65° | — | — |
| 2020 | 76° | 68° | 72° | — | — |
| 2019 | 91° | 60° | 76° | — | — |
| 2018 | 77° | 61° | 69° | — | — |
| 2017 | 75° | 58° | 66° | — | — |
| 2016 | 88° | 61° | 74° | — | — |
| 2015 | 78° | 63° | 70° | — | — |
| 2014 | 79° | 65° | 72° | — | — |
| 2013 | 72° | 59° | 65° | — | — |
| 2012 | 76° | 65° | 70° | 0.03" | — |
| 2011 | 72° | 61° | 66° | — | — |
| 2010 | 74° | 66° | 70° | 0.05" | — |
| 2009 | 81° | 56° | 68° | — | — |
| 2008 | 78° | 56° | 67° | — | — |
| 2007 | 84° | 56° | 70° | — | — |
| 2006 | 78° | 55° | 67° | — | — |
| 2005 | 65° | 62° | 63° | — | — |
| 2004coldest | 67° | 54° | 60° | 0.03" | — |
| 2003 | 89° | 61° | 75° | — | — |
| 2002 | 69° | 60° | 65° | — | — |
| 2001 | 69° | 61° | 65° | — | — |
| 2000 | 74° | 63° | 68° | — | — |
| 1999 | 89° | 57° | 73° | — | — |
| 1998 | 76° | 57° | 66° | — | — |
| 1997 | 75° | 59° | 67° | — | — |
| 1996 | 75° | 54° | 64° | — | — |
| 1995 | 73° | 60° | 67° | — | — |
| 1994 | 81° | 52° | 66° | — | — |
| 1993 | 83° | 56° | 69° | — | — |
| 1992 | 71° | 65° | 68° | 0.2" | — |
| 1991 | 77° | 64° | 71° | — | — |
| 1990warmest | 90° | 65° | 77° | — | — |
| 1989 | 73° | 59° | 66° | 0.15" | — |
| 1988 | 76° | 63° | 69° | — | — |
| 1987 | 79° | 56° | 67° | — | — |
| 1986 | 83° | 52° | 67° | — | — |
| 1985 | 71° | 60° | 66° | — | — |
| 1984 | 78° | 51° | 65° | — | — |
| 1983 | 84° | 60° | 72° | — | — |
| 1982 | 82° | 52° | 67° | — | — |
| 1981 | 77° | 60° | 69° | — | — |
| 1980 | 87° | 50° | 69° | — | — |
| 1979 | 72° | 52° | 62° | — | — |
| 1978 | 82° | 62° | 72° | — | — |
| 1977 | 74° | 56° | 65° | — | — |
| 1976 | 75° | 65° | 70° | — | — |
| 1975 | 74° | 57° | 65° | — | — |
| 1974 | 77° | 58° | 67° | — | — |
| 1973 | 72° | 60° | 66° | — | — |
| 1972 | 73° | 51° | 62° | — | — |
| 1971 | 81° | 50° | 65° | — | — |
55 years of data from SANTA ANA JOHN WAYNE AP