Weather on December 15
Rialto, CA
55 Years of Data
Avg High
64°F
Avg Low
42°F
Warmest
1980
67°F avg
Coldest
1987
39°F avg
About This Date
December 15th in Rialto, CA typically brings mild winter weather, with average highs around 64°F and lows near 42°F. Over 47 years of records, the warmest December 15th was in 1980 (67°F average), while the coldest was 1987 (39°F) — a 28°F range across recorded history. Rain or other precipitation has occurred on about 4% of December 15th dates historically, with the wettest December 15th recording 1.37" of rain.
Planning for December 15th in Rialto, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 82° | 42° | 62° | — | — |
| 2016 | 69° | 48° | 59° | — | — |
| 2015 | 52° | 40° | 46° | — | — |
| 2014 | 60° | 45° | 52° | — | — |
| 2013 | 71° | 58° | 64° | — | — |
| 2012 | 53° | 38° | 45° | — | — |
| 2011 | 50° | 37° | 44° | — | — |
| 2010 | 50° | 46° | 48° | — | — |
| 2009 | 61° | 47° | 54° | — | — |
| 2008 | 44° | 38° | 41° | — | — |
| 2007 | 63° | 46° | 54° | — | — |
| 2006 | 69° | 50° | 60° | — | — |
| 2005 | 66° | 44° | 55° | — | — |
| 2004 | 75° | 59° | 67° | — | — |
| 2003 | 58° | 36° | 47° | — | — |
| 2002 | 63° | 46° | 54° | — | — |
| 2001 | 53° | 41° | 47° | — | — |
| 2000 | 63° | 40° | 51° | — | — |
| 1999 | 67° | 48° | 57° | — | — |
| 1998 | 74° | 57° | 65° | — | — |
| 1997 | 66° | 41° | 54° | — | — |
| 1996 | 53° | 50° | 52° | — | — |
| 1995 | 70° | 47° | 58° | — | — |
| 1994 | 60° | 38° | 49° | — | — |
| 1993 | 54° | 38° | 46° | — | — |
| 1992 | 54° | 36° | 45° | — | — |
| 1991 | 65° | 53° | 59° | — | — |
| 1990 | 54° | 38° | 46° | — | — |
| 1989 | 66° | 42° | 54° | — | — |
| 1988 | 51° | 42° | 47° | 1.37" | — |
| 1987coldest | 50° | 29° | 39° | — | — |
| 1986 | 67° | 42° | 54° | — | — |
| 1985 | 69° | 38° | 53° | — | — |
| 1984 | 59° | 31° | 45° | — | — |
| 1983 | 75° | 44° | 60° | — | — |
| 1982 | 70° | 36° | 53° | — | — |
| 1981 | 77° | 45° | 61° | — | — |
| 1980warmest | 84° | 50° | 67° | — | — |
| 1979 | 78° | 37° | 58° | — | — |
| 1978 | 68° | 37° | 53° | — | — |
| 1977 | 61° | 44° | 52° | 0.03" | — |
| 1976 | 78° | 41° | 60° | — | — |
| 1975 | 60° | 46° | 53° | — | — |
| 1974 | 77° | 41° | 59° | — | — |
| 1973 | 78° | 39° | 59° | — | — |
| 1972 | 65° | 30° | 47° | — | — |
| 1971 | 56° | 34° | 45° | — | — |
47 years of data from FONTANA 5 N