Weather on September 18
San Ramon, CA
55 Years of Data
Avg High
79°F
Avg Low
56°F
Warmest
1984
86°F avg
Coldest
1985
54°F avg
About This Date
September 18th in San Ramon, CA typically brings pleasant fall weather, with average highs around 79°F and lows near 56°F. Over 55 years of records, the warmest September 18th was in 1984 (86°F average), while the coldest was 1985 (54°F) — a 32°F range across recorded history. Rain or other precipitation has occurred on about 13% of September 18th dates historically, with the wettest September 18th recording 1.47" of rain. The last decade has been 2.8°F cooler on this date compared to 20-30 years ago.
The last decade has been 2.8°F cooler on this date compared to 20-30 years ago.
Planning for September 18th in San Ramon, CA? Great weather for outdoor activities.
Cooling Trend
0.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 90° | 71° | 80° | — | — |
| 2024 | 70° | 52° | 61° | — | — |
| 2023 | 67° | 52° | 59° | — | — |
| 2022 | 63° | 51° | 57° | 0.1" | — |
| 2021 | 74° | 49° | 61° | — | — |
| 2020 | 80° | 57° | 69° | — | — |
| 2019 | 75° | 65° | 70° | — | — |
| 2018 | 71° | 45° | 58° | — | — |
| 2017 | 75° | 55° | 65° | — | — |
| 2016 | 88° | 72° | 80° | — | — |
| 2015 | 71° | 54° | 62° | — | — |
| 2014 | 78° | 59° | 69° | 0.3" | — |
| 2013 | 69° | 52° | 60° | — | — |
| 2012 | 77° | 60° | 69° | — | — |
| 2011 | 79° | 56° | 67° | — | — |
| 2010 | 70° | 53° | 61° | — | — |
| 2009 | 85° | 70° | 77° | — | — |
| 2008 | 65° | 44° | 54° | — | — |
| 2007 | 75° | 46° | 61° | — | — |
| 2006 | 91° | 61° | 76° | — | — |
| 2005 | 84° | 48° | 66° | — | — |
| 2004 | 66° | 52° | 59° | — | — |
| 2003 | 93° | 60° | 77° | — | — |
| 2002 | 90° | 55° | 72° | — | — |
| 2001 | 80° | 53° | 67° | — | — |
| 2000 | 101° | 66° | 83° | — | — |
| 1999 | 75° | 52° | 63° | — | — |
| 1998 | 77° | 54° | 65° | — | — |
| 1997 | 79° | 54° | 66° | — | — |
| 1996 | 83° | 57° | 70° | — | — |
| 1995 | 97° | 59° | 78° | — | — |
| 1994 | 88° | 54° | 71° | — | — |
| 1993 | 77° | 52° | 64° | — | — |
| 1992 | 88° | 52° | 70° | — | — |
| 1991 | 94° | 54° | 74° | — | — |
| 1990 | 77° | 56° | 66° | — | — |
| 1989 | 61° | 48° | 54° | 1.47" | — |
| 1988 | 84° | 58° | 71° | — | — |
| 1987 | 86° | 61° | 73° | — | — |
| 1986 | 63° | 46° | 54° | 0.53" | — |
| 1985coldest | 67° | 42° | 54° | 0.23" | — |
| 1984warmest | 96° | 76° | 86° | — | — |
| 1983 | 88° | 64° | 76° | — | — |
| 1982 | 66° | 50° | 58° | 0.15" | — |
| 1981 | 83° | 63° | 73° | — | — |
| 1980 | 79° | 54° | 66° | — | — |
| 1979 | 82° | 56° | 69° | — | — |
| 1978 | 74° | 49° | 61° | — | — |
| 1977 | 67° | 51° | 59° | 0.05" | — |
| 1976 | 79° | 49° | 64° | — | — |
| 1975 | 89° | 63° | 76° | — | — |
| 1974 | 94° | 60° | 77° | — | — |
| 1973 | 76° | 55° | 65° | — | — |
| 1972 | 74° | 47° | 60° | — | — |
| 1971 | 89° | 63° | 76° | — | — |
55 years of data from LIVERMORE CALIFORNIA