Weather on June 21
Rialto, CA
55 Years of Data
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° | — | — |
Rialto, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Rialto, CA Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Rialto, CA Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Rialto, CA
Rialto, CA has no months that meet our "pleasant" threshold — every season has tradeoffs.