Weather on October 21
Sunnyvale, CA
55 Years of Data
Avg High
73°F
Avg Low
53°F
Warmest
2020
70°F avg
Coldest
1971
54°F avg
About This Date
October 21st in Sunnyvale, CA typically brings pleasant fall weather, with average highs around 73°F and lows near 53°F. Over 55 years of records, the warmest October 21st was in 2020 (70°F average), while the coldest was 1971 (54°F) — a 16°F range across recorded history. Rain or other precipitation has occurred on about 9% of October 21st dates historically. The last decade has been 4.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 4.0°F warmer on this date compared to 20-30 years ago.
Planning for October 21st in Sunnyvale, CA? Great weather for outdoor activities.
Warming Trend
0.6°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 75° | 55° | 65° | — | — |
| 2024 | 77° | 53° | 65° | — | — |
| 2023 | 75° | 58° | 66° | — | — |
| 2022 | 72° | 55° | 63° | — | — |
| 2021 | 77° | 62° | 70° | — | — |
| 2020warmest | 87° | 54° | 70° | — | — |
| 2019 | 83° | 51° | 67° | — | — |
| 2018 | 66° | 55° | 61° | — | — |
| 2017 | 70° | 46° | 58° | — | — |
| 2016 | 76° | 52° | 64° | — | — |
| 2015 | 83° | 53° | 68° | — | — |
| 2014 | 72° | 51° | 61° | — | — |
| 2013 | 67° | 53° | 60° | — | — |
| 2012 | 67° | 48° | 57° | 0.13" | — |
| 2011 | 75° | 57° | 66° | — | — |
| 2010 | 69° | 51° | 60° | — | — |
| 2009 | 71° | 56° | 63° | — | — |
| 2008 | 79° | 49° | 64° | — | — |
| 2007 | 74° | 50° | 62° | — | — |
| 2006 | 84° | 50° | 67° | — | — |
| 2005 | 70° | 52° | 61° | — | — |
| 2004 | 66° | 47° | 56° | 0.03" | — |
| 2003 | 80° | 54° | 67° | — | — |
| 2002 | 67° | 50° | 58° | — | — |
| 2001 | 62° | 50° | 56° | — | — |
| 2000 | 71° | 52° | 61° | — | — |
| 1999 | 81° | 52° | 66° | — | — |
| 1998 | 81° | 51° | 66° | — | — |
| 1997 | 71° | 54° | 62° | — | — |
| 1996 | 69° | 43° | 56° | — | — |
| 1995 | 75° | 54° | 64° | — | — |
| 1994 | 76° | 48° | 62° | — | — |
| 1993 | 73° | 56° | 64° | — | — |
| 1992 | 74° | 58° | 66° | — | — |
| 1991 | 75° | 59° | 67° | — | — |
| 1990 | 76° | 49° | 62° | — | — |
| 1989 | 69° | 61° | 65° | 0.43" | — |
| 1988 | 65° | 58° | 61° | — | — |
| 1987 | 71° | 56° | 63° | — | — |
| 1986 | 73° | 56° | 64° | — | — |
| 1985 | 65° | 50° | 57° | 0.03" | — |
| 1984 | 68° | 48° | 58° | — | — |
| 1983 | 72° | 54° | 63° | — | — |
| 1982 | 75° | 59° | 67° | 0.05" | — |
| 1981 | 67° | 55° | 61° | — | — |
| 1980 | 76° | 51° | 63° | — | — |
| 1979 | 70° | 46° | 58° | — | — |
| 1978 | 67° | 54° | 60° | — | — |
| 1977 | 71° | 49° | 60° | — | — |
| 1976 | 70° | 55° | 62° | — | — |
| 1975 | 68° | 55° | 62° | — | — |
| 1974 | 76° | 53° | 64° | — | — |
| 1973 | 74° | 63° | 68° | — | — |
| 1972 | 65° | 54° | 59° | — | — |
| 1971coldest | 67° | 42° | 54° | — | — |
55 years of data from MOFFETT FED AIRFIELD