Weather on August 18
Costa Mesa, CA
55 Years of Data
Avg High
81°F
Avg Low
66°F
Warmest
2020
86°F avg
Coldest
1975
67°F avg
About This Date
August 18th in Costa Mesa, CA typically brings warm summer weather, with average highs around 81°F and lows near 66°F. Over 55 years of records, the warmest August 18th was in 2020 (86°F average), while the coldest was 1975 (67°F) — a 19°F range across recorded history. Rain or other precipitation has occurred on about 2% of August 18th dates historically, with the wettest August 18th recording 0.66" of rain. The last decade has been 3.1°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.1°F warmer on this date compared to 20-30 years ago.
Planning for August 18th in Costa Mesa, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 78° | 66° | 72° | — | — |
| 2024 | 81° | 70° | 75° | — | — |
| 2023 | 82° | 66° | 74° | — | — |
| 2022 | 83° | 69° | 76° | — | — |
| 2021 | 80° | 72° | 76° | — | — |
| 2020warmest | 100° | 71° | 86° | — | — |
| 2019 | 79° | 67° | 73° | — | — |
| 2018 | 82° | 72° | 77° | — | — |
| 2017 | 77° | 67° | 72° | — | — |
| 2016 | 80° | 63° | 71° | — | — |
| 2015 | 78° | 68° | 73° | — | — |
| 2014 | 84° | 69° | 77° | — | — |
| 2013 | 76° | 66° | 71° | — | — |
| 2012 | 89° | 72° | 80° | — | — |
| 2011 | 78° | 63° | 70° | — | — |
| 2010 | 91° | 71° | 81° | — | — |
| 2009 | 75° | 65° | 70° | — | — |
| 2008 | 78° | 66° | 72° | — | — |
| 2007 | 83° | 69° | 76° | — | — |
| 2006 | 79° | 65° | 72° | — | — |
| 2005 | 76° | 65° | 70° | — | — |
| 2004 | 75° | 65° | 70° | — | — |
| 2003 | 79° | 66° | 72° | — | — |
| 2002 | 71° | 65° | 68° | — | — |
| 2001 | 82° | 65° | 73° | — | — |
| 2000 | 83° | 67° | 75° | — | — |
| 1999 | 78° | 62° | 70° | — | — |
| 1998 | 84° | 66° | 75° | — | — |
| 1997 | 86° | 63° | 74° | — | — |
| 1996 | 82° | 66° | 74° | — | — |
| 1995 | 83° | 62° | 72° | — | — |
| 1994 | 86° | 67° | 76° | — | — |
| 1993 | 79° | 65° | 72° | — | — |
| 1992 | 92° | 68° | 80° | — | — |
| 1991 | 79° | 65° | 72° | — | — |
| 1990 | 80° | 67° | 73° | — | — |
| 1989 | 79° | 63° | 71° | — | — |
| 1988 | 78° | 63° | 70° | — | — |
| 1987 | 72° | 62° | 67° | — | — |
| 1986 | 95° | 68° | 82° | — | — |
| 1985 | 82° | 64° | 73° | — | — |
| 1984 | 84° | 79° | 81° | — | — |
| 1983 | 78° | 69° | 74° | — | — |
| 1982 | 83° | 63° | 73° | — | — |
| 1981 | 78° | 68° | 73° | — | — |
| 1980 | 77° | 66° | 72° | — | — |
| 1979 | 77° | 67° | 72° | — | — |
| 1978 | 80° | 58° | 69° | — | — |
| 1977 | 78° | 67° | 72° | 0.66" | — |
| 1976 | 78° | 59° | 69° | — | — |
| 1975coldest | 76° | 59° | 67° | — | — |
| 1974 | 81° | 61° | 71° | — | — |
| 1973 | 86° | 63° | 74° | — | — |
| 1972 | 79° | 63° | 71° | — | — |
| 1971 | 83° | 64° | 73° | — | — |
55 years of data from SANTA ANA JOHN WAYNE AP