Weather on December 18
San Bernardino, CA
55 Years of Data
About This Date
December 18th in San Bernardino, CA typically brings mild winter weather, with average highs around 66°F and lows near 42°F. Over 47 years of records, the warmest December 18th was in 2025 (66°F average), while the coldest was 2006 (44°F) — a 22°F range across recorded history. Rain or other precipitation has occurred on about 17% of December 18th dates historically, with the wettest December 18th recording 2.79" of rain.
Planning for December 18th in San Bernardino, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 82° | 49° | 66° | — | — |
| 2016 | 54° | 43° | 48° | — | — |
| 2015 | 65° | 48° | 56° | — | — |
| 2014 | 60° | 43° | 51° | — | — |
| 2013 | 73° | 52° | 62° | — | — |
| 2012 | 58° | 51° | 54° | 0.33" | — |
| 2011 | 57° | 39° | 48° | 0.05" | — |
| 2010 | 60° | 52° | 56° | 0.71" | — |
| 2009 | 78° | 43° | 60° | — | — |
| 2008 | 53° | 35° | 44° | 1.73" | — |
| 2007 | 59° | 40° | 49° | — | — |
| 2006coldest | 58° | 31° | 44° | — | — |
| 2005 | 59° | 41° | 50° | — | — |
| 2004 | 78° | 39° | 59° | — | — |
| 2003 | 79° | 41° | 60° | — | — |
| 2002 | 57° | 37° | 47° | — | — |
| 2001 | 71° | 35° | 53° | — | — |
| 2000 | 72° | 39° | 55° | — | — |
| 1999 | 77° | 45° | 61° | — | — |
| 1998 | 81° | 46° | 63° | — | — |
| 1997 | 63° | 39° | 51° | — | — |
| 1996 | 65° | 40° | 52° | — | — |
| 1995 | 66° | 37° | 52° | — | — |
| 1994 | 71° | 40° | 55° | — | — |
| 1993 | 61° | 34° | 47° | — | — |
| 1992 | 55° | 44° | 50° | 1.24" | — |
| 1991 | 57° | 50° | 54° | — | — |
| 1990 | 58° | 34° | 46° | — | — |
| 1989 | 57° | 37° | 47° | — | — |
| 1988 | 52° | 43° | 47° | 0.74" | — |
| 1987 | 61° | 38° | 49° | — | — |
| 1986 | 65° | 42° | 53° | — | — |
| 1985 | 76° | 43° | 59° | — | — |
| 1984 | 51° | 40° | 45° | 2.79" | — |
| 1983 | 68° | 43° | 55° | — | — |
| 1982 | 76° | 39° | 57° | — | — |
| 1981 | 77° | 44° | 61° | — | — |
| 1980 | 68° | 42° | 55° | — | — |
| 1979 | 84° | 43° | 63° | — | — |
| 1978 | 53° | 43° | 48° | — | — |
| 1977 | 62° | 51° | 57° | 1.09" | — |
| 1976 | 72° | 39° | 55° | — | — |
| 1975 | 73° | 35° | 54° | — | — |
| 1974 | 77° | 38° | 57° | — | — |
| 1973 | 70° | 40° | 55° | — | — |
| 1972 | 79° | 42° | 60° | — | — |
| 1971 | 65° | 43° | 54° | — | — |
San Bernardino, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
San Bernardino, CA Monthly Precipitation
Average rainfall and snowfall per month, in inches.
San Bernardino, 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 San Bernardino, CA
San Bernardino, CA has no months that meet our "pleasant" threshold — every season has tradeoffs.