Weather on March 21
San Bernardino, CA
55 Years of Data
Avg High
72°F
Avg Low
47°F
Warmest
2026
78°F avg
Coldest
2011
43°F avg
About This Date
March 21st in San Bernardino, CA typically brings pleasant spring weather, with average highs around 72°F and lows near 47°F — a 25°F daily swing. Over 49 years of records, the warmest March 21st was in 2026 (78°F average), while the coldest was 2011 (43°F) — a 35°F range across recorded history. Rain or other precipitation has occurred on about 24% of March 21st dates historically, with the wettest March 21st recording 4.57" of rain.
Planning for March 21st in San Bernardino, CA? Great weather for outdoor activities.
Warming Trend
1.1°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026warmest | 95° | 62° | 78° | — | — |
| 2025 | 79° | 47° | 63° | — | — |
| 2017 | 61° | 52° | 56° | — | — |
| 2016 | 68° | 50° | 59° | — | — |
| 2015 | 80° | 51° | 66° | — | — |
| 2014 | 68° | 50° | 59° | — | — |
| 2013 | 74° | 48° | 61° | — | — |
| 2012 | 79° | 43° | 61° | — | — |
| 2011coldest | 46° | 39° | 43° | 3.33" | — |
| 2010 | 83° | 46° | 64° | — | — |
| 2009 | 68° | 51° | 60° | — | — |
| 2008 | 83° | 42° | 62° | — | — |
| 2007 | 64° | 48° | 56° | 0.97" | — |
| 2006 | 55° | 39° | 47° | — | — |
| 2005 | 70° | 48° | 59° | 0.03" | — |
| 2004 | 87° | 50° | 69° | — | — |
| 2003 | 78° | 45° | 61° | — | — |
| 2002 | 89° | 38° | 63° | — | — |
| 2001 | 81° | 52° | 66° | — | — |
| 2000 | 70° | 52° | 61° | — | — |
| 1999 | 67° | 39° | 53° | — | — |
| 1998 | 72° | 54° | 63° | — | — |
| 1997 | 87° | 50° | 69° | — | — |
| 1996 | 83° | 52° | 67° | — | — |
| 1995 | 65° | 48° | 56° | 0.99" | — |
| 1994 | 72° | 47° | 59° | — | — |
| 1993 | 77° | 50° | 64° | — | — |
| 1992 | 59° | 48° | 54° | 4.57" | — |
| 1991 | 53° | 41° | 47° | 0.18" | — |
| 1990 | 85° | 52° | 68° | — | — |
| 1989 | 81° | 44° | 62° | — | — |
| 1988 | 79° | 48° | 63° | — | — |
| 1987 | 64° | 36° | 50° | 1.07" | — |
| 1986 | 82° | 48° | 65° | — | — |
| 1985 | 69° | 45° | 57° | — | — |
| 1984 | 79° | 49° | 64° | — | — |
| 1983 | 59° | 47° | 53° | 0.97" | — |
| 1982 | 69° | 38° | 53° | — | — |
| 1981 | 68° | 42° | 55° | — | — |
| 1980 | 65° | 41° | 53° | 0.08" | — |
| 1979 | 55° | 43° | 49° | 0.2" | — |
| 1978 | 65° | 55° | 60° | 0.71" | — |
| 1977 | 85° | 44° | 64° | — | — |
| 1976 | 85° | 44° | 64° | — | — |
| 1975 | 64° | 48° | 56° | — | — |
| 1974 | 65° | 52° | 58° | — | — |
| 1973 | 56° | 42° | 49° | 0.05" | — |
| 1972 | 84° | 45° | 64° | — | — |
| 1971 | 75° | 42° | 59° | — | — |
49 years of data from NORTON AFB