Weather on June 21
Rialto, CA
55 Years of Data
Avg High
89°F
Avg Low
59°F
Warmest
2008
90°F avg
Coldest
2003
57°F avg
About This Date
June 21st in Rialto, CA typically brings warm summer weather, with average highs around 89°F and lows near 59°F — a 30°F daily swing. Over 48 years of records, the warmest June 21st was in 2008 (90°F average), while the coldest was 2003 (57°F) — a 33°F range across recorded history. Rain or other precipitation has occurred on about 2% of June 21st dates historically.
Planning for June 21st in Rialto, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 84° | 62° | 73° | — | — |
| 2017 | 101° | 75° | 88° | — | — |
| 2016 | 96° | 70° | 83° | — | — |
| 2015 | 90° | 64° | 77° | — | — |
| 2014 | 89° | 65° | 77° | — | — |
| 2013 | 83° | 58° | 70° | — | — |
| 2012 | 83° | 57° | 70° | — | — |
| 2011 | 92° | 63° | 77° | — | — |
| 2010 | 77° | 54° | 65° | — | — |
| 2009 | 75° | 56° | 65° | — | — |
| 2008warmest | 102° | 77° | 90° | — | — |
| 2007 | 91° | 65° | 78° | — | — |
| 2006 | 91° | 61° | 76° | — | — |
| 2005 | 96° | 61° | 78° | — | — |
| 2004 | 81° | 54° | 67° | — | — |
| 2003coldest | 61° | 53° | 57° | — | — |
| 2002 | 78° | 54° | 66° | — | — |
| 2001 | 100° | 65° | 82° | — | — |
| 2000 | 95° | 57° | 76° | — | — |
| 1999 | 84° | 55° | 70° | — | — |
| 1998 | 86° | 54° | 70° | — | — |
| 1997 | 84° | 54° | 69° | — | — |
| 1996 | 80° | 53° | 67° | — | — |
| 1995 | 84° | 54° | 69° | — | — |
| 1994 | 96° | 52° | 74° | — | — |
| 1993 | 84° | 55° | 70° | — | — |
| 1992 | 85° | 56° | 70° | — | — |
| 1991 | 73° | 50° | 62° | — | — |
| 1990 | 93° | 61° | 77° | — | — |
| 1989 | 101° | 62° | 81° | — | — |
| 1988 | 87° | 54° | 70° | — | — |
| 1987 | 79° | 57° | 68° | — | — |
| 1986 | 92° | 58° | 75° | — | — |
| 1985 | 87° | 57° | 72° | — | — |
| 1984 | 91° | 57° | 74° | — | — |
| 1983 | 82° | 56° | 69° | — | — |
| 1982 | 77° | 60° | 69° | — | — |
| 1981 | 102° | 63° | 82° | — | — |
| 1980 | 93° | 56° | 74° | — | — |
| 1979 | 91° | 54° | 72° | — | — |
| 1978 | 102° | 63° | 82° | — | — |
| 1977 | 89° | 51° | 70° | — | — |
| 1976 | 92° | 58° | 75° | — | — |
| 1975 | 87° | 51° | 69° | — | — |
| 1974 | 97° | 58° | 77° | — | — |
| 1973 | 109° | 61° | 85° | — | — |
| 1972 | 90° | 61° | 75° | 0.43" | — |
| 1971 | 103° | 60° | 81° | — | — |
48 years of data from DEVORE CALIFORNIA