Weather on October 21
Fullerton, CA
55 Years of Data
Avg High
81°F
Avg Low
57°F
Warmest
2003
82°F avg
Coldest
1979
58°F avg
About This Date
October 21st in Fullerton, CA typically brings warm fall weather, with average highs around 81°F and lows near 57°F. Over 55 years of records, the warmest October 21st was in 2003 (82°F average), while the coldest was 1979 (58°F) — a 24°F range across recorded history. Rain or other precipitation has occurred on about 11% of October 21st dates historically, with the wettest October 21st recording 0.89" of rain. The last decade has been 5.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 5.9°F warmer on this date compared to 20-30 years ago.
Planning for October 21st in Fullerton, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.5°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 85° | 57° | 71° | — | — |
| 2024 | 88° | 59° | 73° | — | — |
| 2023 | 85° | 64° | 74° | — | — |
| 2022 | 89° | 63° | 76° | — | — |
| 2021 | 83° | 53° | 68° | — | — |
| 2020 | 79° | 66° | 72° | — | — |
| 2019 | 98° | 62° | 80° | — | — |
| 2018 | 87° | 58° | 72° | — | — |
| 2017 | 82° | 57° | 70° | — | — |
| 2016 | 99° | 62° | 80° | — | — |
| 2015 | 87° | 61° | 74° | — | — |
| 2014 | 82° | 60° | 71° | — | — |
| 2013 | 79° | 53° | 66° | — | — |
| 2012 | 75° | 63° | 69° | — | — |
| 2011 | 75° | 60° | 68° | — | — |
| 2010 | 67° | 61° | 64° | 0.13" | — |
| 2009 | 85° | 54° | 69° | — | — |
| 2008 | 88° | 54° | 71° | — | — |
| 2007 | 84° | 55° | 70° | — | — |
| 2006 | 87° | 54° | 70° | — | — |
| 2005 | 71° | 61° | 66° | — | — |
| 2004 | 69° | 52° | 60° | 0.89" | — |
| 2003warmest | 99° | 65° | 82° | — | — |
| 2002 | 67° | 56° | 61° | — | — |
| 2001 | 76° | 60° | 68° | — | — |
| 2000 | 76° | 59° | 67° | — | — |
| 1999 | 97° | 61° | 79° | — | — |
| 1998 | 79° | 53° | 66° | — | — |
| 1997 | 72° | 57° | 64° | — | — |
| 1996 | 74° | 55° | 64° | — | — |
| 1995 | 77° | 60° | 69° | — | — |
| 1994 | 80° | 50° | 65° | — | — |
| 1993 | 89° | 58° | 73° | — | — |
| 1992 | 79° | 64° | 71° | 0.1" | — |
| 1991 | 78° | 63° | 70° | — | — |
| 1990 | 86° | 61° | 73° | — | — |
| 1989 | 72° | 58° | 65° | 0.15" | — |
| 1988 | 76° | 63° | 69° | — | — |
| 1987 | 79° | 56° | 67° | — | — |
| 1986 | 83° | 52° | 67° | — | — |
| 1985 | 71° | 60° | 66° | — | — |
| 1984 | 78° | 51° | 65° | — | — |
| 1983 | 84° | 60° | 72° | — | — |
| 1982 | 85° | 53° | 69° | — | — |
| 1981 | 91° | 55° | 73° | — | — |
| 1980 | 90° | 52° | 71° | — | — |
| 1979coldest | 74° | 42° | 58° | — | — |
| 1978 | 78° | 48° | 63° | 0.13" | — |
| 1977 | 75° | 52° | 63° | — | — |
| 1976 | 79° | 62° | 70° | — | — |
| 1975 | 70° | 51° | 60° | — | — |
| 1974 | 71° | 59° | 65° | — | — |
| 1973 | 73° | 57° | 65° | — | — |
| 1972 | 75° | 47° | 61° | 0.03" | — |
| 1971 | 84° | 46° | 65° | — | — |
55 years of data from ANAHEIM