Weather on April 21
Rialto, CA
55 Years of Data
Avg High
75°F
Avg Low
51°F
Warmest
2009
81°F avg
Coldest
2010
47°F avg
About This Date
April 21st in Rialto, CA typically brings pleasant spring weather, with average highs around 75°F and lows near 51°F. Over 48 years of records, the warmest April 21st was in 2009 (81°F average), while the coldest was 2010 (47°F) — a 34°F range across recorded history. Rain or other precipitation has occurred on about 8% of April 21st dates historically, with the wettest April 21st recording 1.32" of rain.
Planning for April 21st in Rialto, CA? Great weather for outdoor activities.
Warming Trend
0.3°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 81° | 51° | 66° | — | — |
| 2017 | 86° | 62° | 74° | — | — |
| 2016 | 82° | 55° | 69° | — | — |
| 2015 | 59° | 50° | 55° | — | — |
| 2014 | 83° | 56° | 69° | — | — |
| 2013 | 83° | 57° | 70° | — | — |
| 2012 | 92° | 60° | 76° | — | — |
| 2011 | 61° | 51° | 56° | — | — |
| 2010coldest | 53° | 41° | 47° | — | — |
| 2009warmest | 95° | 67° | 81° | — | — |
| 2008 | 67° | 46° | 56° | — | — |
| 2007 | 54° | 42° | 48° | — | — |
| 2006 | 71° | 50° | 61° | — | — |
| 2005 | 82° | 50° | 66° | — | — |
| 2004 | 72° | 46° | 59° | — | — |
| 2003 | 63° | 45° | 54° | — | — |
| 2002 | 80° | 45° | 62° | — | — |
| 2001 | 56° | 40° | 48° | — | — |
| 2000 | 61° | 49° | 55° | — | — |
| 1999 | 60° | 49° | 54° | — | — |
| 1998 | 93° | 60° | 77° | — | — |
| 1997 | 94° | 59° | 76° | — | — |
| 1996 | 72° | 45° | 58° | — | — |
| 1995 | 66° | 39° | 53° | — | — |
| 1994 | 74° | 56° | 65° | — | — |
| 1993 | 82° | 56° | 69° | — | — |
| 1992 | 77° | 54° | 65° | — | — |
| 1991 | 58° | 47° | 52° | — | — |
| 1990 | 74° | 56° | 65° | — | — |
| 1989 | 77° | 55° | 66° | — | — |
| 1988 | 62° | 45° | 53° | 0.23" | — |
| 1987 | 91° | 51° | 71° | — | — |
| 1986 | 89° | 55° | 72° | — | — |
| 1985 | 57° | 49° | 53° | — | — |
| 1984 | 81° | 58° | 69° | — | — |
| 1983 | 67° | 50° | 58° | 1.32" | — |
| 1982 | 75° | 58° | 66° | — | — |
| 1981 | 85° | 47° | 66° | 0.03" | — |
| 1980 | 71° | 56° | 63° | — | — |
| 1979 | 84° | 46° | 65° | — | — |
| 1978 | 69° | 51° | 60° | — | — |
| 1977 | 85° | 45° | 65° | — | — |
| 1976 | 86° | 50° | 68° | — | — |
| 1975 | 76° | 48° | 62° | — | — |
| 1974 | 85° | 44° | 64° | — | — |
| 1973 | 78° | 44° | 61° | — | — |
| 1972 | 83° | 42° | 62° | — | — |
| 1971 | 58° | 47° | 52° | 0.1" | — |
48 years of data from DEVORE CALIFORNIA