Weather on September 21
El Cajon, CA
55 Years of Data
Avg High
85°F
Avg Low
60°F
Warmest
2015
82°F avg
Coldest
1986
63°F avg
About This Date
September 21st in El Cajon, CA typically brings warm fall weather, with average highs around 85°F and lows near 60°F — a 25°F daily swing. Over 53 years of records, the warmest September 21st was in 2015 (82°F average), while the coldest was 1986 (63°F) — a 19°F range across recorded history. Rain or other precipitation has occurred on about 6% of September 21st dates historically. The last decade has been 1.6°F cooler on this date compared to 20-30 years ago.
The last decade has been 1.6°F cooler on this date compared to 20-30 years ago.
Planning for September 21st in El Cajon, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 79° | 64° | 71° | 0.05" | — |
| 2024 | 78° | 56° | 67° | — | — |
| 2023 | 77° | 56° | 66° | — | — |
| 2022 | 82° | 60° | 71° | — | — |
| 2021 | 101° | 62° | 81° | — | — |
| 2020 | 88° | 63° | 75° | — | — |
| 2019 | 87° | 58° | 72° | — | — |
| 2018 | 85° | 57° | 71° | — | — |
| 2017 | 72° | 66° | 69° | — | — |
| 2016 | 81° | 71° | 76° | 0.48" | — |
| 2015warmest | 95° | 70° | 82° | — | — |
| 2014 | 83° | 65° | 74° | — | — |
| 2013 | 77° | 64° | 71° | — | — |
| 2012 | 90° | 68° | 79° | — | — |
| 2011 | 85° | 60° | 72° | — | — |
| 2010 | 80° | 52° | 66° | — | — |
| 2009 | 93° | 60° | 77° | — | — |
| 2008 | 78° | 61° | 69° | — | — |
| 2007 | 76° | 54° | 65° | — | — |
| 2006 | 85° | 57° | 71° | — | — |
| 2005 | 84° | 61° | 72° | — | — |
| 2004 | 91° | 54° | 72° | — | — |
| 2003 | 91° | 58° | 74° | — | — |
| 2002 | 97° | 59° | 78° | — | — |
| 2001 | 92° | 56° | 74° | — | — |
| 2000 | 86° | 66° | 76° | — | — |
| 1999 | 84° | 62° | 73° | — | — |
| 1998 | 73° | 65° | 69° | — | — |
| 1995 | 88° | 60° | 74° | — | — |
| 1994 | 79° | 63° | 71° | — | — |
| 1993 | 79° | 63° | 71° | — | — |
| 1992 | 96° | 63° | 79° | — | — |
| 1991 | 88° | 64° | 76° | — | — |
| 1990 | 79° | 66° | 72° | — | — |
| 1989 | 94° | 51° | 72° | — | — |
| 1988 | 78° | 58° | 68° | — | — |
| 1987 | 96° | 62° | 79° | 0.46" | — |
| 1986coldest | 76° | 50° | 63° | — | — |
| 1985 | 89° | 56° | 72° | — | — |
| 1984 | 77° | 69° | 73° | — | — |
| 1983 | 93° | 68° | 81° | — | — |
| 1982 | 92° | 56° | 74° | — | — |
| 1981 | 91° | 63° | 77° | — | — |
| 1980 | 82° | 61° | 71° | — | — |
| 1979 | 85° | 66° | 75° | — | — |
| 1978 | 92° | 44° | 68° | — | — |
| 1977 | 82° | 54° | 68° | — | — |
| 1976 | 78° | 66° | 72° | — | — |
| 1975 | 91° | 56° | 73° | — | — |
| 1974 | 101° | 61° | 81° | — | — |
| 1973 | 75° | 59° | 67° | — | — |
| 1972 | 97° | 53° | 75° | — | — |
| 1971 | 77° | 60° | 69° | — | — |
53 years of data from GILLESPIE FLD