Weather on December 9
Rialto, CA
55 Years of Data
Avg High
66°F
Avg Low
44°F
Warmest
1975
72°F avg
Coldest
1972
40°F avg
About This Date
December 9th in Rialto, CA typically brings mild winter weather, with average highs around 66°F and lows near 44°F. Over 47 years of records, the warmest December 9th was in 1975 (72°F average), while the coldest was 1972 (40°F) — a 32°F range across recorded history. Rain or other precipitation has occurred on about 2% of December 9th dates historically.
Planning for December 9th in Rialto, CA? Great weather for outdoor activities.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 82° | 46° | 64° | — | — |
| 2016 | 63° | 46° | 54° | — | — |
| 2015 | 79° | 56° | 67° | — | — |
| 2014 | 74° | 56° | 65° | — | — |
| 2013 | 47° | 37° | 42° | — | — |
| 2012 | 74° | 48° | 61° | — | — |
| 2011 | 68° | 52° | 60° | — | — |
| 2010 | 71° | 51° | 61° | — | — |
| 2009 | 53° | 37° | 45° | — | — |
| 2008 | 61° | 50° | 55° | — | — |
| 2007 | 51° | 41° | 46° | — | — |
| 2006 | 62° | 45° | 53° | — | — |
| 2005 | 67° | 43° | 55° | — | — |
| 2004 | 72° | 44° | 58° | — | — |
| 2003 | 72° | 43° | 57° | — | — |
| 2002 | 69° | 46° | 58° | — | — |
| 2001 | 63° | 38° | 50° | — | — |
| 2000 | 64° | 50° | 57° | — | — |
| 1999 | 65° | 44° | 54° | — | — |
| 1998 | 55° | 46° | 51° | — | — |
| 1997 | 57° | 36° | 46° | — | — |
| 1996 | 58° | 49° | 53° | — | — |
| 1995 | 80° | 59° | 70° | — | — |
| 1994 | 58° | 42° | 50° | — | — |
| 1993 | 67° | 41° | 54° | — | — |
| 1992 | 57° | 41° | 49° | — | — |
| 1991 | 67° | 54° | 60° | — | — |
| 1990 | 73° | 54° | 63° | — | — |
| 1989 | 73° | 42° | 58° | — | — |
| 1988 | 69° | 55° | 62° | — | — |
| 1987 | 65° | 41° | 53° | — | — |
| 1986 | 64° | 38° | 51° | — | — |
| 1985 | 58° | 49° | 53° | — | — |
| 1984 | 70° | 42° | 56° | — | — |
| 1983 | 63° | 44° | 53° | 0.08" | — |
| 1982 | 62° | 41° | 52° | — | — |
| 1981 | 81° | 47° | 64° | — | — |
| 1980 | 67° | 39° | 53° | — | — |
| 1979 | 80° | 44° | 62° | — | — |
| 1978 | 63° | 27° | 45° | — | — |
| 1977 | 69° | 42° | 56° | — | — |
| 1976 | 70° | 36° | 53° | — | — |
| 1975warmest | 78° | 67° | 72° | — | — |
| 1974 | 71° | 41° | 56° | — | — |
| 1973 | 82° | 40° | 61° | — | — |
| 1972coldest | 51° | 28° | 40° | — | — |
| 1971 | 58° | 29° | 43° | — | — |
47 years of data from FONTANA 5 N