Weather on September 20
San Ramon, CA
55 Years of Data
Avg High
81°F
Avg Low
56°F
Warmest
2002
81°F avg
Coldest
2007
49°F avg
About This Date
September 20th in San Ramon, CA typically brings warm fall weather, with average highs around 81°F and lows near 56°F — a 25°F daily swing. Over 55 years of records, the warmest September 20th was in 2002 (81°F average), while the coldest was 2007 (49°F) — a 32°F range across recorded history. Rain or other precipitation has occurred on about 4% of September 20th dates historically. The last decade has been 5.4°F cooler on this date compared to 20-30 years ago.
The last decade has been 5.4°F cooler on this date compared to 20-30 years ago.
Planning for September 20th in San Ramon, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 78° | 61° | 69° | — | — |
| 2024 | 80° | 50° | 65° | — | — |
| 2023 | 74° | 57° | 65° | — | — |
| 2022 | 67° | 51° | 59° | 0.05" | — |
| 2021 | 78° | 56° | 67° | — | — |
| 2020 | 78° | 63° | 70° | — | — |
| 2019 | 75° | 53° | 64° | — | — |
| 2018 | 80° | 57° | 69° | — | — |
| 2017 | 69° | 52° | 60° | — | — |
| 2016 | 91° | 66° | 79° | — | — |
| 2015 | 87° | 64° | 76° | — | — |
| 2014 | 76° | 62° | 69° | — | — |
| 2013 | 84° | 58° | 71° | — | — |
| 2012 | 77° | 62° | 70° | — | — |
| 2011 | 88° | 73° | 80° | — | — |
| 2010 | 65° | 53° | 59° | — | — |
| 2009 | 80° | 63° | 71° | — | — |
| 2008 | 64° | 40° | 52° | — | — |
| 2007coldest | 63° | 35° | 49° | — | — |
| 2006 | 85° | 54° | 69° | — | — |
| 2005 | 81° | 59° | 70° | — | — |
| 2004 | 71° | 48° | 60° | — | — |
| 2003 | 101° | 61° | 81° | — | — |
| 2002warmest | 98° | 65° | 81° | — | — |
| 2001 | 85° | 53° | 69° | — | — |
| 2000 | 98° | 60° | 79° | — | — |
| 1999 | 80° | 54° | 67° | — | — |
| 1998 | 79° | 54° | 66° | — | — |
| 1997 | 89° | 61° | 75° | — | — |
| 1996 | 90° | 56° | 73° | — | — |
| 1995 | 92° | 62° | 77° | — | — |
| 1994 | 92° | 55° | 73° | — | — |
| 1993 | 84° | 57° | 71° | — | — |
| 1992 | 90° | 55° | 72° | — | — |
| 1991 | 84° | 56° | 70° | — | — |
| 1990 | 95° | 59° | 77° | — | — |
| 1989 | 73° | 46° | 60° | — | — |
| 1988 | 80° | 43° | 61° | — | — |
| 1987 | 88° | 65° | 76° | — | — |
| 1986 | 60° | 43° | 51° | 0.05" | — |
| 1985 | 79° | 57° | 68° | — | — |
| 1984 | 91° | 55° | 73° | — | — |
| 1983 | 87° | 65° | 76° | — | — |
| 1982 | 70° | 52° | 61° | — | — |
| 1981 | 82° | 58° | 70° | — | — |
| 1980 | 72° | 52° | 62° | — | — |
| 1979 | 83° | 61° | 72° | — | — |
| 1978 | 73° | 54° | 63° | — | — |
| 1977 | 68° | 52° | 60° | — | — |
| 1976 | 85° | 49° | 67° | — | — |
| 1975 | 84° | 50° | 67° | — | — |
| 1974 | 92° | 62° | 77° | — | — |
| 1973 | 76° | 56° | 66° | — | — |
| 1972 | 73° | 51° | 62° | — | — |
| 1971 | 90° | 61° | 75° | — | — |
55 years of data from LIVERMORE CALIFORNIA