Weather on December 21
Riverside, CA
55 Years of Data
Avg High
67°F
Avg Low
41°F
Warmest
2020
66°F avg
Coldest
1990
40°F avg
About This Date
December 21st in Riverside, CA typically brings mild winter weather, with average highs around 67°F and lows near 41°F — a 26°F daily swing. Over 55 years of records, the warmest December 21st was in 2020 (66°F average), while the coldest was 1990 (40°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 20% of December 21st dates historically, with the wettest December 21st recording 3.45" of rain. The last decade has been 6.8°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.8°F warmer on this date compared to 20-30 years ago.
Planning for December 21st in Riverside, CA? Great weather for outdoor activities.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 75° | 46° | 61° | — | — |
| 2024 | 73° | 43° | 58° | — | — |
| 2023 | 70° | 52° | 61° | — | — |
| 2022 | 75° | 39° | 57° | — | — |
| 2021 | 67° | 47° | 57° | — | — |
| 2020warmest | 84° | 49° | 66° | — | — |
| 2019 | 73° | 44° | 59° | — | — |
| 2018 | 71° | 49° | 60° | — | — |
| 2017 | 61° | 46° | 53° | — | — |
| 2016 | 67° | 51° | 59° | 1.24" | — |
| 2015 | 60° | 39° | 50° | 0.1" | — |
| 2014 | 67° | 43° | 55° | — | — |
| 2013 | 58° | 40° | 49° | — | — |
| 2012 | 64° | 36° | 50° | — | — |
| 2011 | 64° | 39° | 52° | — | — |
| 2010 | 56° | 52° | 54° | 3.45" | — |
| 2009 | 63° | 47° | 55° | — | — |
| 2008 | 64° | 37° | 51° | — | — |
| 2007 | 60° | 45° | 52° | — | — |
| 2006 | 62° | 30° | 46° | — | — |
| 2005 | 84° | 44° | 64° | — | — |
| 2004 | 71° | 41° | 56° | — | — |
| 2003 | 64° | 42° | 53° | — | — |
| 2002 | 57° | 45° | 51° | 0.1" | — |
| 2001 | 53° | 38° | 45° | 0.74" | — |
| 2000 | 74° | 35° | 54° | — | — |
| 1999 | 75° | 41° | 58° | — | — |
| 1998 | 55° | 36° | 45° | — | — |
| 1997 | 58° | 38° | 48° | 0.38" | — |
| 1996 | 63° | 35° | 49° | — | — |
| 1995 | 67° | 36° | 51° | — | — |
| 1994 | 82° | 40° | 61° | — | — |
| 1993 | 69° | 38° | 53° | — | — |
| 1992 | 66° | 31° | 48° | — | — |
| 1991 | 74° | 43° | 58° | — | — |
| 1990coldest | 50° | 30° | 40° | — | — |
| 1989 | 68° | 37° | 53° | — | — |
| 1988 | 65° | 51° | 58° | 1.22" | — |
| 1987 | 73° | 36° | 54° | — | — |
| 1986 | 70° | 40° | 55° | — | — |
| 1985 | 81° | 38° | 59° | — | — |
| 1984 | 62° | 34° | 48° | — | — |
| 1983 | 61° | 42° | 51° | — | — |
| 1982 | 63° | 41° | 52° | — | — |
| 1981 | 65° | 50° | 57° | 0.03" | — |
| 1980 | 79° | 40° | 59° | — | — |
| 1979 | 60° | 48° | 54° | 0.2" | — |
| 1978 | 66° | 33° | 50° | — | — |
| 1977 | 65° | 55° | 60° | 0.1" | — |
| 1976 | 70° | 37° | 53° | — | — |
| 1975 | 65° | 37° | 51° | 0.03" | — |
| 1974 | 73° | 37° | 55° | — | — |
| 1973 | 66° | 37° | 52° | — | — |
| 1972 | 79° | 43° | 61° | — | — |
| 1971 | 62° | 36° | 49° | — | — |
55 years of data from RIVERSIDE MUNI AP