Weather on August 20
Fullerton, CA
55 Years of Data
Avg High
86°F
Avg Low
64°F
Warmest
2007
85°F avg
Coldest
1975
66°F avg
About This Date
August 20th in Fullerton, CA typically brings warm summer weather, with average highs around 86°F and lows near 64°F. Over 55 years of records, the warmest August 20th was in 2007 (85°F average), while the coldest was 1975 (66°F) — a 19°F range across recorded history. Rain or other precipitation has occurred on about 2% of August 20th dates historically, with the wettest August 20th recording 3.2" of rain. The last decade has been 5.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 5.0°F warmer on this date compared to 20-30 years ago.
Planning for August 20th in Fullerton, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 93° | 66° | 80° | — | — |
| 2024 | 97° | 65° | 81° | — | — |
| 2023 | 79° | 72° | 75° | 3.2" | — |
| 2022 | 87° | 68° | 78° | — | — |
| 2021 | 84° | 68° | 76° | — | — |
| 2020 | 97° | 73° | 85° | — | — |
| 2019 | 88° | 63° | 75° | — | — |
| 2018 | 87° | 71° | 79° | — | — |
| 2017 | 82° | 67° | 74° | — | — |
| 2016 | 89° | 64° | 77° | — | — |
| 2015 | 87° | 69° | 78° | — | — |
| 2014 | 86° | 67° | 76° | — | — |
| 2013 | 88° | 64° | 76° | — | — |
| 2012 | 91° | 70° | 80° | — | — |
| 2011 | 82° | 64° | 73° | — | — |
| 2010 | 94° | 65° | 79° | — | — |
| 2009 | 83° | 62° | 72° | — | — |
| 2008 | 81° | 65° | 73° | — | — |
| 2007warmest | 98° | 72° | 85° | — | — |
| 2006 | 85° | 63° | 74° | — | — |
| 2005 | 86° | 63° | 74° | — | — |
| 2004 | 82° | 65° | 73° | — | — |
| 2003 | 76° | 61° | 68° | — | — |
| 2002 | 76° | 61° | 68° | — | — |
| 2001 | 90° | 64° | 77° | — | — |
| 2000 | 89° | 59° | 74° | — | — |
| 1999 | 85° | 62° | 73° | — | — |
| 1998 | 85° | 60° | 72° | — | — |
| 1997 | 87° | 70° | 78° | — | — |
| 1996 | 86° | 61° | 73° | — | — |
| 1995 | 83° | 65° | 74° | — | — |
| 1994 | 87° | 68° | 78° | — | — |
| 1993 | 83° | 62° | 72° | — | — |
| 1992 | 95° | 68° | 82° | — | — |
| 1991 | 84° | 63° | 73° | — | — |
| 1990 | 79° | 63° | 71° | — | — |
| 1989 | 76° | 64° | 70° | — | — |
| 1988 | 77° | 60° | 69° | — | — |
| 1987 | 80° | 61° | 70° | — | — |
| 1986 | 94° | 69° | 81° | — | — |
| 1985 | 80° | 60° | 70° | — | — |
| 1984 | 83° | 69° | 76° | — | — |
| 1983 | 82° | 68° | 75° | — | — |
| 1982 | 99° | 61° | 80° | — | — |
| 1981 | 98° | 55° | 77° | — | — |
| 1980 | 86° | 55° | 71° | — | — |
| 1979 | 82° | 63° | 72° | — | — |
| 1978 | 88° | 52° | 70° | — | — |
| 1977 | 94° | 65° | 79° | — | — |
| 1976 | 85° | 65° | 75° | — | — |
| 1975coldest | 79° | 53° | 66° | — | — |
| 1974 | 83° | 60° | 71° | — | — |
| 1973 | 86° | 65° | 75° | — | — |
| 1972 | 90° | 54° | 72° | — | — |
| 1971 | 86° | 60° | 73° | — | — |
55 years of data from ANAHEIM