Weather on August 17
Rialto, CA
55 Years of Data
Avg High
93°F
Avg Low
64°F
Warmest
1992
88°F avg
Coldest
1976
69°F avg
About This Date
August 17th in Rialto, CA typically brings hot summer weather, with average highs around 93°F and lows near 64°F — a 29°F daily swing. Over 48 years of records, the warmest August 17th was in 1992 (88°F average), while the coldest was 1976 (69°F) — a 19°F range across recorded history. Rain or other precipitation has occurred on about 4% of August 17th dates historically, with the wettest August 17th recording 6.35" of rain.
Planning for August 17th in Rialto, 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 | 91° | 63° | 77° | — | — |
| 2017 | 85° | 61° | 73° | — | — |
| 2016 | 99° | 71° | 85° | — | — |
| 2015 | 93° | 68° | 81° | — | — |
| 2014 | 95° | 69° | 82° | — | — |
| 2013 | 96° | 71° | 84° | — | — |
| 2012 | 96° | 78° | 87° | — | — |
| 2011 | 96° | 67° | 81° | — | — |
| 2010 | 97° | 72° | 84° | — | — |
| 2009 | 89° | 59° | 74° | — | — |
| 2008 | 89° | 62° | 76° | — | — |
| 2007 | 98° | 74° | 86° | — | — |
| 2006 | 89° | 57° | 73° | — | — |
| 2005 | 89° | 59° | 74° | — | — |
| 2004 | 95° | 63° | 79° | — | — |
| 2003 | 103° | 71° | 87° | — | — |
| 2002 | 90° | 58° | 74° | — | — |
| 2001 | 102° | 73° | 88° | — | — |
| 2000 | 97° | 69° | 83° | — | — |
| 1999 | 101° | 68° | 84° | — | — |
| 1998 | 88° | 60° | 74° | — | — |
| 1997 | 90° | 59° | 74° | — | — |
| 1996 | 94° | 64° | 79° | — | — |
| 1995 | 88° | 58° | 73° | — | — |
| 1994 | 95° | 71° | 83° | — | — |
| 1993 | 91° | 57° | 74° | — | — |
| 1992warmest | 101° | 75° | 88° | — | — |
| 1991 | 85° | 61° | 73° | — | — |
| 1990 | 89° | 60° | 75° | — | — |
| 1989 | 87° | 58° | 72° | — | — |
| 1988 | 90° | 59° | 74° | — | — |
| 1987 | 85° | 57° | 71° | — | — |
| 1986 | 103° | 60° | 81° | — | — |
| 1985 | 86° | 62° | 74° | — | — |
| 1984 | 100° | 71° | 86° | — | — |
| 1983 | 92° | 67° | 79° | 6.35" | — |
| 1982 | 96° | 63° | 79° | — | — |
| 1981 | 100° | 62° | 81° | — | — |
| 1980 | 86° | 64° | 75° | — | — |
| 1979 | 93° | 61° | 77° | — | — |
| 1978 | 84° | 69° | 77° | — | — |
| 1977 | 76° | 67° | 71° | 5.44" | — |
| 1976coldest | 83° | 56° | 69° | — | — |
| 1975 | 88° | 54° | 71° | — | — |
| 1974 | 99° | 56° | 77° | — | — |
| 1973 | 100° | 66° | 83° | — | — |
| 1972 | 91° | 55° | 73° | — | — |
| 1971 | 100° | 65° | 82° | — | — |
48 years of data from FONTANA 5 N