Weather on August 31
Rialto, CA
55 Years of Data
Avg High
95°F
Avg Low
65°F
Warmest
2007
93°F avg
Coldest
1992
64°F avg
About This Date
August 31st in Rialto, CA typically brings hot summer weather, with average highs around 95°F and lows near 65°F — a 30°F daily swing. Over 46 years of records, the warmest August 31st was in 2007 (93°F average), while the coldest was 1992 (64°F) — a 29°F range across recorded history. This date has historically been dry, with little recorded precipitation.
Planning for August 31st in Rialto, CA? Stay hydrated and seek shade during peak afternoon hours.
Warming Trend
0.8°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2017 | 106° | 75° | 90° | — | — |
| 2016 | 98° | 74° | 86° | — | — |
| 2015 | 89° | 65° | 77° | — | — |
| 2014 | 94° | 70° | 82° | — | — |
| 2013 | 90° | 73° | 81° | — | — |
| 2012 | 91° | 70° | 80° | — | — |
| 2011 | 90° | 62° | 76° | — | — |
| 2010 | 88° | 56° | 72° | — | — |
| 2009 | 97° | 74° | 85° | — | — |
| 2008 | 85° | 66° | 75° | — | — |
| 2007warmest | 105° | 80° | 93° | — | — |
| 2006 | 96° | 67° | 81° | — | — |
| 2005 | 94° | 62° | 78° | — | — |
| 2004 | 104° | 69° | 87° | — | — |
| 2003 | 99° | 65° | 82° | — | — |
| 2002 | 97° | 68° | 82° | — | — |
| 2001 | 92° | 60° | 76° | — | — |
| 2000 | 79° | 58° | 68° | — | — |
| 1999 | 90° | 56° | 73° | — | — |
| 1998 | 105° | 67° | 86° | — | — |
| 1997 | 97° | 64° | 80° | — | — |
| 1996 | 99° | 68° | 83° | — | — |
| 1995 | 103° | 74° | 88° | — | — |
| 1994 | 88° | 60° | 74° | — | — |
| 1993 | 94° | 60° | 77° | — | — |
| 1992coldest | 77° | 52° | 64° | — | — |
| 1991 | 92° | 63° | 77° | — | — |
| 1990 | 91° | 62° | 77° | — | — |
| 1989 | 91° | 54° | 72° | — | — |
| 1988 | 97° | 68° | 82° | — | — |
| 1987 | 99° | 66° | 82° | — | — |
| 1985 | 103° | 70° | 86° | — | — |
| 1984 | 101° | 71° | 86° | — | — |
| 1983 | 99° | 64° | 81° | — | — |
| 1982 | 100° | 64° | 82° | — | — |
| 1981 | 96° | 60° | 78° | — | — |
| 1980 | 91° | 57° | 74° | — | — |
| 1979 | 92° | 58° | 75° | — | — |
| 1978 | 93° | 73° | 83° | — | — |
| 1977 | 90° | 64° | 77° | — | — |
| 1976 | 104° | 68° | 86° | — | — |
| 1975 | 97° | 57° | 77° | — | — |
| 1974 | 101° | 58° | 79° | — | — |
| 1973 | 86° | 55° | 71° | — | — |
| 1972 | 97° | 66° | 81° | — | — |
| 1971 | 95° | 54° | 74° | — | — |
46 years of data from FONTANA 5 N