Weather on December 21
San Jose, CA
55 Years of Data
Avg High
58°F
Avg Low
42°F
Warmest
2025
63°F avg
Coldest
1990
33°F avg
About This Date
December 21st in San Jose, CA typically brings cool winter weather, with average highs around 58°F and lows near 42°F. Over 55 years of records, the warmest December 21st was in 2025 (63°F average), while the coldest was 1990 (33°F) — a 30°F range across recorded history. Rain or other precipitation has occurred on about 33% of December 21st dates historically, with the wettest December 21st recording 4.01" of rain. The last decade has been 1.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.5°F warmer on this date compared to 20-30 years ago.
Planning for December 21st in San Jose, CA? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Warming Trend
1.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 65° | 61° | 63° | — | — |
| 2024 | 65° | 51° | 58° | — | — |
| 2023 | 61° | 48° | 54° | — | — |
| 2022 | 61° | 38° | 49° | — | — |
| 2021 | 60° | 37° | 49° | 0.25" | — |
| 2020 | 60° | 34° | 47° | — | — |
| 2019 | 60° | 44° | 52° | — | — |
| 2018 | 61° | 50° | 55° | — | — |
| 2017 | 58° | 35° | 46° | — | — |
| 2016 | 65° | 40° | 52° | — | — |
| 2015 | 59° | 52° | 55° | 1.24" | — |
| 2014 | 62° | 56° | 59° | — | — |
| 2013 | 60° | 36° | 48° | — | — |
| 2012 | 57° | 47° | 52° | 0.05" | — |
| 2011 | 63° | 36° | 49° | — | — |
| 2010 | 59° | 49° | 54° | 0.3" | — |
| 2009 | 60° | 47° | 53° | 0.51" | — |
| 2008 | 52° | 42° | 47° | 0.25" | — |
| 2007 | 53° | 35° | 44° | — | — |
| 2006 | 52° | 40° | 46° | 1.09" | — |
| 2005 | 67° | 58° | 62° | 0.74" | — |
| 2004 | 67° | 39° | 53° | — | — |
| 2003 | 60° | 47° | 53° | 0.33" | — |
| 2002 | 58° | 48° | 53° | 0.38" | — |
| 2001 | 54° | 43° | 48° | 0.76" | — |
| 2000 | 62° | 37° | 50° | — | — |
| 1999 | 72° | 40° | 56° | — | — |
| 1998 | 45° | 27° | 36° | — | — |
| 1997 | 55° | 42° | 49° | — | — |
| 1996 | 51° | 48° | 50° | 4.01" | — |
| 1995 | 58° | 40° | 49° | — | — |
| 1994 | 52° | 37° | 44° | — | — |
| 1993 | 50° | 33° | 42° | — | — |
| 1992 | 55° | 45° | 50° | — | — |
| 1991 | 56° | 34° | 45° | — | — |
| 1990coldest | 38° | 29° | 33° | — | — |
| 1989 | 56° | 39° | 47° | — | — |
| 1988 | 55° | 38° | 46° | 0.28" | — |
| 1987 | 56° | 39° | 47° | — | — |
| 1986 | 58° | 39° | 48° | — | — |
| 1985 | 56° | 33° | 44° | — | — |
| 1984 | 54° | 35° | 44° | — | — |
| 1983 | 52° | 36° | 44° | — | — |
| 1982 | 59° | 52° | 55° | 1.5" | — |
| 1981 | 60° | 52° | 56° | 0.1" | — |
| 1980 | 64° | 47° | 55° | 0.53" | — |
| 1979 | 59° | 47° | 53° | 0.18" | — |
| 1978 | 51° | 31° | 41° | — | — |
| 1977 | 62° | 50° | 56° | — | — |
| 1976 | 57° | 34° | 45° | — | — |
| 1975 | 58° | 38° | 48° | — | — |
| 1974 | 59° | 39° | 49° | — | — |
| 1973 | 59° | 47° | 53° | 0.51" | — |
| 1972 | 59° | 50° | 55° | — | — |
| 1971 | 57° | 32° | 45° | — | — |
55 years of data from SAN JOSE