Weather on December 9
Costa Mesa, CA
55 Years of Data
Avg High
70°F
Avg Low
47°F
Warmest
1988
72°F avg
Coldest
1998
33°F avg
About This Date
December 9th in Costa Mesa, CA typically brings pleasant winter weather, with average highs around 70°F and lows near 47°F. Over 55 years of records, the warmest December 9th was in 1988 (72°F average), while the coldest was 1998 (33°F) — a 39°F range across recorded history. Rain or other precipitation has occurred on about 16% of December 9th dates historically, with the wettest December 9th recording 1.65" of rain. The last decade has been 6.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.4°F warmer on this date compared to 20-30 years ago.
Planning for December 9th in Costa Mesa, CA? Great weather for outdoor activities.
Warming Trend
0.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 82° | 51° | 67° | — | — |
| 2024 | 68° | 54° | 61° | — | — |
| 2023 | 76° | 48° | 62° | — | — |
| 2022 | 63° | 46° | 54° | — | — |
| 2021 | 62° | 54° | 58° | 0.18" | — |
| 2020 | 74° | 54° | 64° | — | — |
| 2019 | 68° | 52° | 60° | — | — |
| 2018 | 71° | 50° | 61° | — | — |
| 2017 | 87° | 49° | 68° | — | — |
| 2016 | 64° | 51° | 58° | — | — |
| 2015 | 74° | 53° | 63° | — | — |
| 2014 | 76° | 56° | 66° | — | — |
| 2013 | 63° | 41° | 52° | — | — |
| 2012 | 69° | 54° | 61° | — | — |
| 2011 | 70° | 43° | 56° | — | — |
| 2010 | 70° | 51° | 60° | — | — |
| 2009 | 58° | 44° | 51° | — | — |
| 2008 | 73° | 48° | 61° | — | — |
| 2007 | 64° | 45° | 54° | 0.08" | — |
| 2006 | 66° | 51° | 59° | 0.51" | — |
| 2005 | 74° | 52° | 63° | 0.13" | — |
| 2004 | 64° | 48° | 56° | 0.03" | — |
| 2003 | 68° | 44° | 56° | — | — |
| 2002 | 65° | 52° | 58° | — | — |
| 2001 | 61° | 44° | 52° | — | — |
| 2000 | 66° | 56° | 61° | — | — |
| 1999 | 66° | 44° | 55° | — | — |
| 1998coldest | 66° | 0° | 33° | — | — |
| 1997 | 68° | 40° | 54° | — | — |
| 1996 | 70° | 52° | 61° | 1.65" | — |
| 1995 | 70° | 54° | 62° | — | — |
| 1994 | 69° | 39° | 54° | — | — |
| 1993 | 67° | 45° | 56° | — | — |
| 1992 | 64° | 45° | 54° | — | — |
| 1991 | 73° | 51° | 62° | 0.15" | — |
| 1990 | 81° | 46° | 63° | — | — |
| 1989 | 76° | 47° | 61° | — | — |
| 1988warmest | 79° | 66° | 72° | — | — |
| 1987 | 70° | 45° | 57° | — | — |
| 1986 | 69° | 45° | 57° | — | — |
| 1985 | 65° | 40° | 52° | — | — |
| 1984 | 70° | 48° | 59° | — | — |
| 1983 | 69° | 48° | 59° | 0.33" | — |
| 1982 | 67° | 59° | 63° | 0.03" | — |
| 1981 | 79° | 49° | 64° | — | — |
| 1980 | 70° | 41° | 55° | — | — |
| 1979 | 73° | 45° | 59° | — | — |
| 1978 | 63° | 36° | 49° | — | — |
| 1977 | 69° | 52° | 60° | — | — |
| 1976 | 68° | 44° | 56° | — | — |
| 1975 | 80° | 47° | 63° | — | — |
| 1974 | 72° | 35° | 53° | — | — |
| 1973 | 83° | 45° | 64° | — | — |
| 1972 | 54° | 34° | 44° | — | — |
| 1971 | 59° | 38° | 48° | — | — |
55 years of data from SANTA ANA JOHN WAYNE AP