Weather on December 21
Vallejo, CA
55 Years of Data
Avg High
54°F
Avg Low
40°F
Warmest
2025
59°F avg
Coldest
1990
30°F avg
About This Date
December 21st in Vallejo, CA typically brings cool winter weather, with average highs around 54°F and lows near 40°F. Over 55 years of records, the warmest December 21st was in 2025 (59°F average), while the coldest was 1990 (30°F) — a 29°F range across recorded history. Rain or other precipitation has occurred on about 35% of December 21st dates historically, with the wettest December 21st recording 2.79" of rain. The last decade has been 2.2°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.2°F warmer on this date compared to 20-30 years ago.
Planning for December 21st in Vallejo, CA? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Warming Trend
1.1°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 61° | 57° | 59° | 0.46" | — |
| 2024 | 52° | 43° | 47° | 0.36" | — |
| 2023 | 65° | 47° | 56° | — | — |
| 2022 | 53° | 40° | 46° | — | — |
| 2021 | 48° | 41° | 45° | — | — |
| 2020 | 55° | 37° | 46° | — | — |
| 2019 | 59° | 44° | 52° | — | — |
| 2018 | 57° | 49° | 53° | 0.28" | — |
| 2017 | 61° | 38° | 49° | — | — |
| 2016 | 59° | 44° | 52° | — | — |
| 2015 | 56° | 46° | 51° | 2.57" | — |
| 2014 | 65° | 52° | 58° | — | — |
| 2013 | 63° | 31° | 47° | — | — |
| 2012 | 57° | 49° | 53° | 0.43" | — |
| 2011 | 58° | 27° | 42° | — | — |
| 2010 | 53° | 46° | 50° | 0.58" | — |
| 2009 | 57° | 42° | 50° | 0.15" | — |
| 2008 | 46° | 39° | 43° | 0.64" | — |
| 2007 | 56° | 27° | 41° | — | — |
| 2006 | 47° | 40° | 43° | 0.48" | — |
| 2005 | 60° | 55° | 58° | 1.17" | — |
| 2004 | 63° | 35° | 49° | — | — |
| 2003 | 60° | 39° | 50° | — | — |
| 2002 | 55° | 41° | 48° | 0.23" | — |
| 2001 | 52° | — | — | 1.7" | — |
| 2000 | 58° | 37° | 47° | — | — |
| 1999 | 67° | 45° | 56° | — | — |
| 1998 | 46° | 23° | 35° | — | — |
| 1997 | 60° | 36° | 48° | — | — |
| 1996 | 51° | 38° | 44° | 2.79" | — |
| 1995 | 47° | 43° | 45° | — | — |
| 1994 | 48° | 40° | 44° | — | — |
| 1993 | 42° | 33° | 38° | — | — |
| 1992 | 52° | 38° | 45° | — | — |
| 1991 | 53° | 35° | 44° | — | — |
| 1990coldest | 39° | 22° | 30° | — | — |
| 1989 | 42° | 35° | 39° | — | — |
| 1988 | 55° | 38° | 46° | 2.03" | — |
| 1987 | 52° | 37° | 44° | — | — |
| 1986 | 46° | 36° | 41° | — | — |
| 1985 | 40° | 33° | 36° | — | — |
| 1984 | 52° | 30° | 41° | — | — |
| 1983 | 50° | 34° | 42° | — | — |
| 1982 | 56° | 44° | 50° | 0.89" | — |
| 1981 | 60° | 51° | 56° | 0.84" | — |
| 1980 | 53° | 43° | 48° | — | — |
| 1979 | 58° | 45° | 51° | 1.19" | — |
| 1978 | 51° | 28° | 40° | — | — |
| 1977 | 54° | 41° | 47° | 0.05" | — |
| 1976 | 60° | 37° | 49° | — | — |
| 1975 | 57° | 36° | 46° | — | — |
| 1974 | 59° | 41° | 50° | — | — |
| 1973 | 54° | 42° | 48° | 0.64" | — |
| 1972 | 57° | 50° | 54° | — | — |
| 1971 | 52° | 35° | 43° | — | — |
55 years of data from VALLEJO