Weather on March 21
Sunnyvale, CA
55 Years of Data
Avg High
65°F
Avg Low
48°F
Warmest
2026
73°F avg
Coldest
1975
47°F avg
About This Date
March 21st in Sunnyvale, CA typically brings mild spring weather, with average highs around 65°F and lows near 48°F. Over 56 years of records, the warmest March 21st was in 2026 (73°F average), while the coldest was 1975 (47°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 30% of March 21st dates historically, with the wettest March 21st recording 2.11" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for March 21st in Sunnyvale, CA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Warming Trend
0.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026warmest | 86° | 59° | 73° | — | — |
| 2025 | 63° | 45° | 54° | — | — |
| 2024 | 73° | 49° | 61° | — | — |
| 2023 | 56° | 47° | 51° | 2.11" | — |
| 2022 | 73° | 45° | 59° | — | — |
| 2021 | 66° | 40° | 53° | — | — |
| 2020 | 62° | 45° | 53° | — | — |
| 2019 | 62° | 44° | 53° | — | — |
| 2018 | 68° | 55° | 62° | — | — |
| 2017 | 68° | 56° | 62° | 0.2" | — |
| 2016 | 67° | 49° | 58° | 0.43" | — |
| 2015 | 71° | 50° | 61° | — | — |
| 2014 | 68° | 48° | 58° | — | — |
| 2013 | 65° | 47° | 56° | — | — |
| 2012 | 72° | 47° | 59° | — | — |
| 2011 | 58° | 44° | 51° | 0.41" | — |
| 2010 | 65° | 47° | 56° | — | — |
| 2009 | 63° | 49° | 56° | 0.43" | — |
| 2008 | 66° | 42° | 54° | — | — |
| 2007 | 67° | 47° | 57° | — | — |
| 2006 | 58° | 43° | 50° | 0.1" | — |
| 2005 | 64° | 50° | 57° | 0.46" | — |
| 2004 | 67° | 54° | 60° | — | — |
| 2003 | 65° | 45° | 55° | — | — |
| 2002 | 64° | 48° | 56° | — | — |
| 2001 | 65° | 53° | 59° | — | — |
| 2000 | 74° | 48° | 61° | — | — |
| 1999 | 61° | 49° | 55° | 0.03" | — |
| 1998 | 66° | 54° | 60° | — | — |
| 1997 | 79° | 57° | 68° | — | — |
| 1996 | 71° | 46° | 59° | — | — |
| 1995 | 56° | 44° | 50° | 0.58" | — |
| 1994 | 63° | 49° | 56° | — | — |
| 1993 | 66° | 50° | 58° | — | — |
| 1992 | 68° | 53° | 61° | 0.2" | — |
| 1991 | 55° | 47° | 51° | 0.43" | — |
| 1990 | 72° | 50° | 61° | — | — |
| 1989 | 67° | 55° | 61° | — | — |
| 1988 | 68° | 50° | 59° | — | — |
| 1987 | 54° | 44° | 49° | 1.32" | — |
| 1986 | 67° | 48° | 57° | — | — |
| 1985 | 61° | 45° | 53° | — | — |
| 1984 | 65° | 49° | 57° | — | — |
| 1983 | 63° | 44° | 53° | — | — |
| 1982 | 63° | 46° | 54° | — | — |
| 1981 | 66° | 51° | 59° | 0.38" | — |
| 1980 | 62° | 46° | 54° | 0.28" | — |
| 1979 | 63° | 51° | 57° | — | — |
| 1978 | 67° | 57° | 62° | 1.19" | — |
| 1977 | 73° | 44° | 59° | — | — |
| 1976 | 74° | 49° | 61° | — | — |
| 1975coldest | 54° | 40° | 47° | 1.96" | — |
| 1974 | 64° | 44° | 54° | — | — |
| 1973 | 56° | 47° | 51° | 0.36" | — |
| 1972 | 66° | 53° | 60° | — | — |
| 1971 | 60° | 43° | 51° | — | — |
56 years of data from MOFFETT FED AIRFIELD