Weather on August 18
Fontana, CA
55 Years of Data
Avg High
92°F
Avg Low
64°F
Warmest
2020
92°F avg
Coldest
1976
68°F avg
About This Date
August 18th in Fontana, CA typically brings hot summer weather, with average highs around 92°F and lows near 64°F — a 28°F daily swing. Over 55 years of records, the warmest August 18th was in 2020 (92°F average), while the coldest was 1976 (68°F) — a 24°F range across recorded history. Rain or other precipitation has occurred on about 4% of August 18th dates historically, with the wettest August 18th recording 1.22" of rain. The last decade has been 1.9°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.9°F warmer on this date compared to 20-30 years ago.
Planning for August 18th in Fontana, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
1.1°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 93° | 62° | 78° | — | — |
| 2024 | 94° | 63° | 78° | — | — |
| 2023 | 96° | 65° | 80° | — | — |
| 2022 | 96° | 68° | 82° | — | — |
| 2021 | 79° | 70° | 74° | — | — |
| 2020warmest | 108° | 76° | 92° | — | — |
| 2019 | 88° | 61° | 74° | — | — |
| 2018 | 94° | 69° | 81° | — | — |
| 2017 | 89° | 63° | 76° | — | — |
| 2016 | 100° | 66° | 83° | — | — |
| 2015 | 91° | 66° | 79° | — | — |
| 2014 | 98° | 67° | 82° | — | — |
| 2013 | 95° | 65° | 80° | — | — |
| 2012 | 99° | 76° | 87° | — | — |
| 2011 | 95° | 64° | 80° | — | — |
| 2010 | 98° | 72° | 85° | — | — |
| 2009 | 89° | 59° | 74° | — | — |
| 2008 | 90° | 63° | 76° | — | — |
| 2007 | 100° | 71° | 86° | — | — |
| 2006 | 92° | 62° | 77° | — | — |
| 2005 | 87° | 59° | 73° | — | — |
| 2004 | 90° | 63° | 76° | — | — |
| 2003 | 97° | 67° | 82° | — | — |
| 2002 | 81° | 64° | 72° | — | — |
| 2001 | 99° | 68° | 83° | — | — |
| 2000 | 94° | 68° | 81° | — | — |
| 1999 | 93° | 64° | 79° | — | — |
| 1998 | 88° | 62° | 75° | — | — |
| 1997 | 98° | 61° | 79° | — | — |
| 1996 | 96° | 63° | 79° | — | — |
| 1995 | 95° | 60° | 78° | — | — |
| 1994 | 96° | 70° | 83° | — | — |
| 1993 | 93° | 62° | 78° | — | — |
| 1992 | 105° | 71° | 88° | — | — |
| 1991 | 92° | 63° | 77° | — | — |
| 1990 | 88° | 62° | 75° | — | — |
| 1989 | 86° | 59° | 73° | — | — |
| 1988 | 92° | 60° | 76° | — | — |
| 1987 | 87° | 59° | 73° | — | — |
| 1986 | 103° | 69° | 86° | — | — |
| 1985 | 88° | 58° | 73° | — | — |
| 1984 | 89° | 69° | 79° | — | — |
| 1983 | 73° | 68° | 71° | 1.22" | — |
| 1982 | 99° | 62° | 80° | — | — |
| 1981 | 89° | 64° | 77° | — | — |
| 1980 | 84° | 61° | 72° | — | — |
| 1979 | 85° | 62° | 73° | — | — |
| 1978 | 92° | 50° | 71° | — | — |
| 1977 | 70° | 66° | 68° | 0.08" | — |
| 1976coldest | 79° | 57° | 68° | — | — |
| 1975 | 86° | 57° | 72° | — | — |
| 1974 | 93° | 62° | 78° | — | — |
| 1973 | 100° | 68° | 84° | — | — |
| 1972 | 86° | 63° | 74° | — | — |
| 1971 | 99° | 68° | 83° | — | — |
55 years of data from FONTANA KAISER