Weather on September 20
San Bernardino, CA
55 Years of Data
Avg High
88°F
Avg Low
59°F
Warmest
2015
85°F avg
Coldest
1988
57°F avg
About This Date
September 20th in San Bernardino, CA typically brings warm fall weather, with average highs around 88°F and lows near 59°F — a 29°F daily swing. Over 48 years of records, the warmest September 20th was in 2015 (85°F average), while the coldest was 1988 (57°F) — a 28°F range across recorded history. Rain or other precipitation has occurred on about 4% of September 20th dates historically.
Planning for September 20th in San Bernardino, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 91° | 64° | 78° | — | — |
| 2017 | 72° | 60° | 66° | — | — |
| 2016 | 81° | 67° | 74° | — | — |
| 2015warmest | 99° | 71° | 85° | — | — |
| 2014 | 82° | 62° | 72° | — | — |
| 2013 | 78° | 61° | 69° | — | — |
| 2012 | 102° | 64° | 83° | — | — |
| 2011 | 95° | 60° | 78° | — | — |
| 2010 | 92° | 54° | 73° | — | — |
| 2009 | 94° | 59° | 76° | — | — |
| 2008 | 85° | 58° | 71° | — | — |
| 2007 | 71° | 56° | 63° | — | — |
| 2006 | 87° | 53° | 70° | — | — |
| 2005 | 78° | 64° | 71° | 0.46" | — |
| 2004 | 77° | 53° | 65° | — | — |
| 2003 | 99° | 59° | 79° | — | — |
| 2002 | 96° | 58° | 77° | — | — |
| 2001 | 91° | 57° | 74° | — | — |
| 2000 | 88° | 63° | 75° | — | — |
| 1999 | 95° | 51° | 73° | — | — |
| 1998 | 74° | 60° | 67° | — | — |
| 1997 | 87° | 60° | 74° | — | — |
| 1996 | 91° | 59° | 75° | — | — |
| 1995 | 95° | 59° | 77° | — | — |
| 1994 | 89° | 57° | 73° | — | — |
| 1993 | 78° | 56° | 67° | — | — |
| 1992 | 97° | 59° | 78° | — | — |
| 1991 | 91° | 65° | 78° | — | — |
| 1990 | 78° | 62° | 70° | — | — |
| 1989 | 82° | 50° | 66° | — | — |
| 1988coldest | 60° | 54° | 57° | 0.15" | — |
| 1987 | 95° | 60° | 78° | — | — |
| 1986 | 73° | 53° | 63° | — | — |
| 1985 | 91° | 56° | 73° | — | — |
| 1984 | 99° | 69° | 84° | — | — |
| 1983 | 85° | 67° | 76° | — | — |
| 1982 | 94° | 55° | 74° | — | — |
| 1981 | 96° | — | — | — | — |
| 1980 | 87° | 55° | 71° | — | — |
| 1979 | 103° | 64° | 83° | — | — |
| 1978 | 84° | 65° | 74° | — | — |
| 1977 | 81° | 53° | 67° | — | — |
| 1976 | 78° | 63° | 70° | — | — |
| 1975 | 95° | 62° | 79° | — | — |
| 1974 | 96° | 59° | 78° | — | — |
| 1973 | 82° | 54° | 68° | — | — |
| 1972 | 97° | 51° | 74° | — | — |
| 1971 | 90° | 49° | 69° | — | — |
48 years of data from NORTON AFB