Weather on September 30
San Ramon, CA
55 Years of Data
Avg High
79°F
Avg Low
55°F
Warmest
1978
84°F avg
Coldest
2019
50°F avg
About This Date
September 30th in San Ramon, CA typically brings pleasant fall weather, with average highs around 79°F and lows near 55°F. Over 55 years of records, the warmest September 30th was in 1978 (84°F average), while the coldest was 2019 (50°F) — a 34°F range across recorded history. Rain or other precipitation has occurred on about 11% of September 30th dates historically, with the wettest September 30th recording 2.06" of rain. The last decade has been 6.3°F cooler on this date compared to 20-30 years ago.
The last decade has been 6.3°F cooler on this date compared to 20-30 years ago.
Planning for September 30th in San Ramon, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 64° | 55° | 60° | 0.13" | — |
| 2024 | 82° | 50° | 66° | — | — |
| 2023 | 63° | 48° | 55° | — | — |
| 2022 | 79° | 57° | 68° | 0.03" | — |
| 2021 | 80° | 60° | 70° | — | — |
| 2020 | 90° | 73° | 81° | — | — |
| 2019coldest | 59° | 41° | 50° | — | — |
| 2018 | 65° | 51° | 58° | — | — |
| 2017 | 75° | 51° | 63° | — | — |
| 2016 | 89° | 52° | 70° | — | — |
| 2015 | 70° | 57° | 63° | — | — |
| 2014 | 73° | 54° | 63° | — | — |
| 2013 | 69° | 53° | 61° | 0.05" | — |
| 2012 | 88° | 72° | 80° | — | — |
| 2011 | 85° | 53° | 69° | — | — |
| 2010 | 95° | 70° | 82° | — | — |
| 2009 | 63° | 44° | 53° | — | — |
| 2008 | 83° | 60° | 71° | — | — |
| 2007 | 69° | 42° | 56° | — | — |
| 2006 | 66° | 51° | 59° | — | — |
| 2005 | 97° | 61° | 79° | — | — |
| 2004 | 73° | 53° | 63° | — | — |
| 2003 | 88° | 53° | 70° | — | — |
| 2002 | 76° | 52° | 64° | — | — |
| 2001 | 92° | 63° | 77° | — | — |
| 2000 | 95° | 61° | 78° | — | — |
| 1999 | 96° | 66° | 81° | — | — |
| 1998 | 72° | 53° | 62° | — | — |
| 1997 | 87° | 58° | 72° | — | — |
| 1996 | 65° | 52° | 58° | — | — |
| 1995 | 85° | 51° | 68° | — | — |
| 1994 | 82° | 52° | 67° | — | — |
| 1993 | 89° | 57° | 73° | — | — |
| 1992 | 84° | 58° | 71° | — | — |
| 1991 | 85° | 56° | 70° | — | — |
| 1990 | 95° | 30° | 63° | — | — |
| 1989 | 67° | 47° | 57° | — | — |
| 1988 | 92° | 64° | 78° | — | — |
| 1987 | 95° | 72° | 83° | — | — |
| 1986 | 77° | 50° | 64° | — | — |
| 1985 | 62° | 45° | 53° | — | — |
| 1984 | 82° | 50° | 66° | — | — |
| 1983 | 61° | 51° | 56° | 2.06" | — |
| 1982 | 67° | 48° | 57° | — | — |
| 1981 | 73° | 54° | 63° | — | — |
| 1980 | 89° | 62° | 76° | — | — |
| 1979 | 81° | 63° | 72° | — | — |
| 1978warmest | 97° | 72° | 84° | — | — |
| 1977 | 58° | 47° | 52° | — | — |
| 1976 | 74° | 59° | 66° | 0.08" | — |
| 1975 | 86° | — | — | — | — |
| 1974 | 89° | 47° | 68° | — | — |
| 1973 | 89° | 55° | 72° | — | — |
| 1972 | 65° | 52° | 58° | — | — |
| 1971 | 62° | 40° | 51° | 0.43" | — |
55 years of data from LIVERMORE CALIFORNIA