Weather on September 1
Sunnyvale, CA
55 Years of Data
Avg High
80°F
Avg Low
59°F
Warmest
2017
86°F avg
Coldest
1975
60°F avg
About This Date
September 1st in Sunnyvale, CA typically brings warm fall weather, with average highs around 80°F and lows near 59°F. Over 55 years of records, the warmest September 1st was in 2017 (86°F average), while the coldest was 1975 (60°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 2% of September 1st dates historically. The last decade has been 2.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 2.9°F warmer on this date compared to 20-30 years ago.
Planning for September 1st in Sunnyvale, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 90° | 61° | 75° | — | — |
| 2024 | 79° | 60° | 69° | — | — |
| 2023 | 77° | 61° | 69° | — | — |
| 2022 | 90° | 60° | 75° | — | — |
| 2021 | 81° | 57° | 69° | — | — |
| 2020 | 75° | 57° | 66° | — | — |
| 2019 | 84° | 61° | 72° | — | — |
| 2018 | 72° | 58° | 65° | — | — |
| 2017warmest | 106° | 67° | 86° | — | — |
| 2016 | 72° | 59° | 65° | — | — |
| 2015 | 79° | 58° | 68° | — | — |
| 2014 | 85° | 60° | 72° | — | — |
| 2013 | 80° | 62° | 71° | — | — |
| 2012 | 70° | 58° | 64° | — | — |
| 2011 | 79° | 56° | 67° | — | — |
| 2010 | 92° | 58° | 75° | — | — |
| 2009 | 80° | 60° | 70° | — | — |
| 2008 | 87° | 54° | 70° | — | — |
| 2007 | 87° | 62° | 75° | — | — |
| 2006 | 74° | 58° | 66° | — | — |
| 2005 | 76° | 59° | 67° | — | — |
| 2004 | 74° | 60° | 67° | — | — |
| 2003 | 82° | 58° | 70° | — | — |
| 2002 | 93° | 60° | 77° | — | — |
| 2001 | 78° | 58° | 68° | — | — |
| 2000 | 65° | 56° | 60° | 0.13" | — |
| 1999 | 76° | 53° | 64° | — | — |
| 1998 | 78° | 59° | 69° | — | — |
| 1997 | 81° | 61° | 71° | — | — |
| 1996 | 82° | 56° | 69° | — | — |
| 1995 | 73° | 58° | 65° | — | — |
| 1994 | 79° | 57° | 68° | — | — |
| 1993 | 82° | 63° | 72° | — | — |
| 1992 | 77° | 60° | 69° | — | — |
| 1991 | 75° | 62° | 69° | — | — |
| 1990 | 79° | 58° | 68° | — | — |
| 1989 | 77° | 59° | 68° | — | — |
| 1988 | 74° | 61° | 67° | — | — |
| 1987 | 80° | 64° | 72° | — | — |
| 1986 | 80° | 60° | 70° | — | — |
| 1985 | 83° | 62° | 72° | — | — |
| 1984 | 93° | 60° | 77° | — | — |
| 1983 | 79° | 62° | 70° | — | — |
| 1982 | 83° | 57° | 70° | — | — |
| 1981 | 80° | 58° | 69° | — | — |
| 1980 | 70° | 58° | 64° | — | — |
| 1979 | 81° | 58° | 69° | — | — |
| 1978 | 88° | 61° | 74° | — | — |
| 1977 | 73° | 56° | 64° | — | — |
| 1976 | 75° | 60° | 68° | — | — |
| 1975coldest | 71° | 49° | 60° | — | — |
| 1974 | 72° | 60° | 66° | — | — |
| 1973 | 79° | 54° | 66° | — | — |
| 1972 | 74° | 62° | 68° | — | — |
| 1971 | 76° | 56° | 66° | — | — |
55 years of data from MOFFETT FED AIRFIELD