Weather on May 20
Fontana, CA
55 Years of Data
Avg High
81°F
Avg Low
55°F
Warmest
1988
79°F avg
Coldest
1975
56°F avg
About This Date
May 20th in Fontana, CA typically brings warm spring weather, with average highs around 81°F and lows near 55°F — a 26°F daily swing. Over 55 years of records, the warmest May 20th was in 1988 (79°F average), while the coldest was 1975 (56°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 2% of May 20th dates historically, with the wettest May 20th recording 0.51" of rain. The last decade has been 2.2°F cooler on this date compared to 20-30 years ago.
The last decade has been 2.2°F cooler on this date compared to 20-30 years ago.
Planning for May 20th in Fontana, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 94° | 59° | 76° | — | — |
| 2024 | 71° | 55° | 63° | — | — |
| 2023 | 85° | 60° | 72° | — | — |
| 2022 | 65° | 55° | 60° | — | — |
| 2021 | 73° | 58° | 65° | — | — |
| 2020 | 80° | 54° | 67° | — | — |
| 2019 | 71° | 53° | 62° | — | — |
| 2018 | 71° | 58° | 64° | — | — |
| 2017 | 96° | 59° | 78° | — | — |
| 2016 | 72° | 56° | 64° | — | — |
| 2015 | 76° | 56° | 66° | — | — |
| 2014 | 72° | 55° | 63° | — | — |
| 2013 | 95° | 58° | 76° | — | — |
| 2012 | 97° | 57° | 77° | — | — |
| 2011 | 74° | 51° | 62° | — | — |
| 2010 | 83° | 54° | 68° | — | — |
| 2009 | 89° | 59° | 74° | — | — |
| 2008 | 81° | 61° | 71° | — | — |
| 2007 | 76° | 54° | 65° | — | — |
| 2006 | 85° | 61° | 73° | — | — |
| 2005 | 91° | 63° | 77° | — | — |
| 2004 | 74° | 55° | 64° | — | — |
| 2003 | 97° | 60° | 78° | — | — |
| 2002 | 64° | 51° | 58° | 0.51" | — |
| 2001 | 80° | 57° | 69° | — | — |
| 2000 | 98° | 60° | 79° | — | — |
| 1999 | 72° | 55° | 63° | — | — |
| 1998 | 78° | 51° | 65° | — | — |
| 1997 | 81° | 62° | 71° | — | — |
| 1996 | 82° | 55° | 69° | — | — |
| 1995 | 78° | 59° | 69° | — | — |
| 1994 | 79° | 49° | 64° | — | — |
| 1993 | 79° | 61° | 70° | — | — |
| 1992 | 76° | 59° | 67° | — | — |
| 1991 | 77° | 48° | 63° | — | — |
| 1990 | 78° | 55° | 67° | — | — |
| 1989 | 80° | 34° | 57° | — | — |
| 1988warmest | 100° | 57° | 79° | — | — |
| 1987 | 69° | 56° | 62° | — | — |
| 1986 | 89° | 52° | 70° | — | — |
| 1985 | 81° | 54° | 67° | — | — |
| 1984 | 86° | 51° | 69° | — | — |
| 1983 | 90° | 48° | 69° | — | — |
| 1982 | 79° | 50° | 64° | — | — |
| 1981 | 67° | 49° | 58° | — | — |
| 1980 | 87° | 57° | 72° | — | — |
| 1979 | 79° | 54° | 66° | — | — |
| 1978 | 91° | 50° | 71° | — | — |
| 1977 | 89° | 51° | 70° | — | — |
| 1976 | 82° | 55° | 69° | — | — |
| 1975coldest | 61° | 51° | 56° | — | — |
| 1974 | 81° | 43° | 62° | — | — |
| 1973 | 75° | 52° | 63° | — | — |
| 1972 | 67° | 49° | 58° | — | — |
| 1971 | 86° | 55° | 71° | — | — |
55 years of data from FONTANA KAISER