Weather on May 21
Sunnyvale, CA
55 Years of Data
Avg High
73°F
Avg Low
53°F
Warmest
2000
79°F avg
Coldest
1974
56°F avg
About This Date
May 21st in Sunnyvale, CA typically brings pleasant spring weather, with average highs around 73°F and lows near 53°F. Over 55 years of records, the warmest May 21st was in 2000 (79°F average), while the coldest was 1974 (56°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 4% of May 21st dates historically. 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 May 21st in Sunnyvale, CA? Great weather for outdoor activities.
Warming Trend
0.4°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 75° | 52° | 64° | — | — |
| 2024 | 83° | 52° | 67° | — | — |
| 2023 | 79° | 57° | 68° | — | — |
| 2022 | 84° | 52° | 68° | — | — |
| 2021 | 70° | 48° | 59° | — | — |
| 2020 | 79° | 51° | 65° | — | — |
| 2019 | 62° | 53° | 58° | 0.2" | — |
| 2018 | 71° | 53° | 62° | — | — |
| 2017 | 83° | 58° | 70° | — | — |
| 2016 | 64° | 53° | 59° | — | — |
| 2015 | 67° | 55° | 61° | — | — |
| 2014 | 75° | 55° | 65° | — | — |
| 2013 | 73° | 52° | 62° | — | — |
| 2012 | 70° | 53° | 61° | — | — |
| 2011 | 71° | 51° | 61° | — | — |
| 2010 | 63° | 49° | 56° | — | — |
| 2009 | 73° | 50° | 62° | — | — |
| 2008 | 71° | 51° | 61° | — | — |
| 2007 | 78° | 54° | 66° | — | — |
| 2006 | 68° | 55° | 62° | — | — |
| 2005 | 78° | 52° | 65° | — | — |
| 2004 | 63° | 56° | 59° | — | — |
| 2003 | 79° | 56° | 67° | — | — |
| 2002 | 66° | 49° | 57° | 0.03" | — |
| 2001 | 82° | 58° | 70° | — | — |
| 2000warmest | 96° | 62° | 79° | — | — |
| 1999 | 74° | 47° | 60° | — | — |
| 1998 | 68° | 49° | 58° | — | — |
| 1997 | 81° | 54° | 67° | — | — |
| 1996 | 73° | 52° | 62° | — | — |
| 1995 | 67° | 55° | 61° | — | — |
| 1994 | 70° | 50° | 60° | — | — |
| 1993 | 74° | 58° | 66° | — | — |
| 1992 | 82° | 55° | 69° | — | — |
| 1991 | 72° | 54° | 63° | — | — |
| 1990 | 75° | 55° | 65° | — | — |
| 1989 | 68° | 52° | 60° | — | — |
| 1988 | 86° | 62° | 74° | — | — |
| 1987 | 68° | 54° | 61° | — | — |
| 1986 | 68° | 52° | 60° | — | — |
| 1985 | 73° | 51° | 62° | — | — |
| 1984 | 75° | 51° | 63° | — | — |
| 1983 | 76° | 60° | 68° | — | — |
| 1982 | 67° | 54° | 60° | — | — |
| 1981 | 68° | 54° | 61° | — | — |
| 1980 | 76° | 52° | 64° | — | — |
| 1979 | 76° | 58° | 67° | — | — |
| 1978 | 69° | 55° | 62° | — | — |
| 1977 | 68° | 51° | 60° | — | — |
| 1976 | 71° | 50° | 61° | — | — |
| 1975 | 80° | 50° | 65° | — | — |
| 1974coldest | 68° | 44° | 56° | — | — |
| 1973 | 68° | 50° | 59° | — | — |
| 1972 | 69° | 56° | 62° | — | — |
| 1971 | 68° | 48° | 58° | — | — |
55 years of data from MOFFETT FED AIRFIELD