Weather on October 21
Rialto, CA
55 Years of Data
About This Date
October 21st in Rialto, CA typically brings pleasant fall weather, with average highs around 78°F and lows near 55°F. Over 48 years of records, the warmest October 21st was in 2003 (88°F average), while the coldest was 2004 (55°F) — a 33°F range across recorded history. Rain or other precipitation has occurred on about 6% of October 21st dates historically.
Planning for October 21st in Rialto, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 91° | 55° | 73° | — | — |
| 2017 | 77° | 55° | 66° | — | — |
| 2016 | 91° | 65° | 78° | — | — |
| 2015 | 78° | 59° | 69° | — | — |
| 2014 | 78° | 58° | 68° | — | — |
| 2013 | 83° | 56° | 69° | — | — |
| 2012 | 65° | 58° | 61° | — | — |
| 2011 | 78° | 49° | 63° | — | — |
| 2010 | 59° | 55° | 57° | — | — |
| 2009 | 80° | 62° | 71° | — | — |
| 2008 | 89° | 66° | 78° | — | — |
| 2007 | 70° | 57° | 63° | — | — |
| 2006 | 83° | 61° | 72° | — | — |
| 2005 | 88° | 57° | 72° | — | — |
| 2004coldest | 65° | 46° | 55° | — | — |
| 2003warmest | 103° | 73° | 88° | — | — |
| 2002 | 68° | 46° | 57° | — | — |
| 2001 | 78° | 54° | 66° | — | — |
| 2000 | 62° | 54° | 58° | — | — |
| 1999 | 95° | 66° | 81° | — | — |
| 1998 | 85° | 58° | 71° | — | — |
| 1997 | 72° | 58° | 65° | — | — |
| 1996 | 68° | 51° | 60° | — | — |
| 1995 | 77° | 53° | 65° | — | — |
| 1994 | 80° | 47° | 63° | — | — |
| 1993 | 86° | 60° | 73° | — | — |
| 1992 | 64° | 55° | 60° | — | — |
| 1991 | 73° | 55° | 64° | — | — |
| 1990 | 82° | 46° | 64° | — | — |
| 1989 | 68° | 56° | 62° | 0.13" | — |
| 1988 | 81° | 57° | 69° | — | — |
| 1987 | 78° | 55° | 67° | — | — |
| 1986 | 80° | 47° | 63° | — | — |
| 1985 | 68° | 56° | 62° | 0.05" | — |
| 1984 | 75° | 49° | 62° | — | — |
| 1983 | 90° | 53° | 71° | — | — |
| 1982 | 84° | 53° | 69° | — | — |
| 1981 | 84° | 50° | 67° | — | — |
| 1980 | 89° | 51° | 70° | — | — |
| 1979 | 76° | 48° | 62° | — | — |
| 1978 | 79° | 58° | 68° | — | — |
| 1977 | 74° | 56° | 65° | — | — |
| 1976 | 80° | 62° | 71° | 0.13" | — |
| 1975 | 78° | 52° | 65° | — | — |
| 1974 | 72° | 57° | 64° | — | — |
| 1973 | 80° | 47° | 63° | — | — |
| 1972 | 72° | 47° | 59° | — | — |
| 1971 | 87° | 43° | 65° | — | — |
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.