Weather on December 21
Santa Rosa, CA
55 Years of Data
Avg High
56°F
Avg Low
40°F
Warmest
2025
61°F avg
Coldest
1990
31°F avg
About This Date
December 21st in Santa Rosa, CA typically brings cool winter weather, with average highs around 56°F and lows near 40°F. Over 55 years of records, the warmest December 21st was in 2025 (61°F average), while the coldest was 1990 (31°F) — a 30°F range across recorded history. Rain or other precipitation has occurred on about 47% of December 21st dates historically, with the wettest December 21st recording 4.14" of rain. The last decade has been 3.2°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.2°F warmer on this date compared to 20-30 years ago.
Planning for December 21st in Santa Rosa, CA? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Warming Trend
1.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 63° | 60° | 61° | 2.95" | — |
| 2024 | 60° | 47° | 53° | 1.32" | — |
| 2023 | 66° | 50° | 58° | 0.08" | — |
| 2022 | 60° | 37° | 49° | — | — |
| 2021 | 52° | 41° | 46° | 0.33" | — |
| 2020 | 59° | 33° | 46° | — | — |
| 2019 | 59° | 41° | 50° | — | — |
| 2018 | 60° | 51° | 56° | 0.84" | — |
| 2017 | 59° | 31° | 45° | — | — |
| 2016 | 63° | 44° | 53° | — | — |
| 2015 | 56° | 47° | 51° | — | — |
| 2014 | 61° | 55° | 58° | — | — |
| 2013 | 66° | 48° | 57° | — | — |
| 2012 | 52° | 46° | 49° | — | — |
| 2011 | 64° | 30° | 47° | — | — |
| 2010 | 55° | 45° | 50° | 0.05" | — |
| 2009 | 56° | 51° | 53° | 0.48" | — |
| 2008 | 49° | 41° | 45° | 1.45" | — |
| 2007 | 55° | 29° | 42° | — | — |
| 2006 | 48° | 43° | 45° | 1.7" | — |
| 2005 | 60° | 54° | 57° | 1.32" | — |
| 2004 | 72° | 32° | 52° | — | — |
| 2003 | 61° | 43° | 52° | 0.3" | — |
| 2002 | 56° | 40° | 48° | 1.68" | — |
| 2001 | 53° | 40° | 46° | 0.76" | — |
| 2000 | 54° | 37° | 45° | 0.18" | — |
| 1999 | 71° | 39° | 55° | — | — |
| 1998 | 46° | 26° | 36° | — | — |
| 1997 | 57° | 39° | 48° | — | — |
| 1996 | 49° | 43° | 46° | 4.14" | — |
| 1995 | 57° | 36° | 46° | — | — |
| 1994 | 50° | 37° | 44° | — | — |
| 1993 | 48° | 30° | 39° | — | — |
| 1992 | 54° | 43° | 48° | 0.08" | — |
| 1991 | 54° | 33° | 43° | — | — |
| 1990coldest | 41° | 21° | 31° | — | — |
| 1989 | 56° | 36° | 46° | — | — |
| 1988 | 52° | 37° | 44° | 0.64" | — |
| 1987 | 55° | 34° | 44° | 0.18" | — |
| 1986 | 55° | 32° | 44° | — | — |
| 1985 | 48° | 29° | 38° | — | — |
| 1984 | 54° | 30° | 42° | — | — |
| 1983 | 53° | 33° | 43° | — | — |
| 1982 | 55° | 52° | 53° | 2.72" | — |
| 1981 | — | 48° | — | 0.43" | — |
| 1980 | 52° | 47° | 49° | — | — |
| 1979 | 59° | 47° | 53° | 1.83" | — |
| 1978 | 59° | 26° | 43° | — | — |
| 1977 | 58° | 43° | 50° | — | — |
| 1976 | 60° | 28° | 44° | — | — |
| 1975 | 55° | 36° | 45° | 0.48" | — |
| 1974 | 57° | 37° | 47° | 0.1" | — |
| 1973 | 52° | 47° | 49° | 3.3" | — |
| 1972 | 57° | 50° | 54° | 0.08" | — |
| 1971 | 45° | 35° | 40° | 0.05" | — |
55 years of data from SANTA ROSA