Weather on December 19
Ontario, CA
55 Years of Data
Avg High
66°F
Avg Low
42°F
Warmest
2024
67°F avg
Coldest
1978
44°F avg
About This Date
December 19th in Ontario, CA typically brings mild winter weather, with average highs around 66°F and lows near 42°F. Over 41 years of records, the warmest December 19th was in 2024 (67°F average), while the coldest was 1978 (44°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 17% of December 19th dates historically, with the wettest December 19th recording 1.42" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for December 19th in Ontario, CA? Great weather for outdoor activities.
Warming Trend
0.9°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 77° | 51° | 64° | — | — |
| 2024warmest | 84° | 50° | 67° | — | — |
| 2023 | 65° | 54° | 59° | 0.15" | — |
| 2022 | 65° | 37° | 51° | — | — |
| 2021 | 67° | 39° | 53° | — | — |
| 2020 | 72° | 42° | 57° | — | — |
| 2019 | 66° | 35° | 51° | — | — |
| 2018 | 75° | 48° | 62° | — | — |
| 2017 | 69° | 43° | 56° | — | — |
| 2016 | 70° | 33° | 51° | — | — |
| 2015 | 63° | 38° | 50° | 0.43" | — |
| 2014 | 64° | 46° | 55° | — | — |
| 2013 | 56° | 45° | 50° | 0.61" | — |
| 2012 | 58° | 33° | 45° | — | — |
| 2011 | 56° | 48° | 52° | — | — |
| 2010 | 59° | 53° | 56° | 1.37" | — |
| 2009 | 77° | 48° | 63° | — | — |
| 2008 | 54° | 38° | 46° | — | — |
| 2007 | 61° | 51° | 56° | 0.94" | — |
| 2006 | 57° | 35° | 46° | — | — |
| 2005 | 70° | 43° | 56° | — | — |
| 2004 | 79° | 40° | 59° | — | — |
| 2003 | 76° | 44° | 60° | — | — |
| 2002 | 59° | 38° | 48° | — | — |
| 2001 | 74° | 38° | 56° | — | — |
| 2000 | 75° | 41° | 58° | — | — |
| 1999 | 78° | 41° | 60° | — | — |
| 1998 | 57° | 50° | 54° | 0.15" | — |
| 1983 | 55° | 36° | 45° | — | — |
| 1982 | 78° | 40° | 59° | — | — |
| 1981 | 72° | 45° | 58° | — | — |
| 1980 | 66° | 37° | 52° | — | — |
| 1979 | 67° | 44° | 55° | — | — |
| 1978coldest | 51° | 38° | 44° | 1.42" | — |
| 1977 | 59° | 36° | 47° | — | — |
| 1976 | 66° | 41° | 54° | — | — |
| 1975 | 65° | 38° | 51° | — | — |
| 1974 | 67° | 40° | 53° | — | — |
| 1973 | 70° | 41° | 55° | — | — |
| 1972 | 65° | 44° | 54° | — | — |
| 1971 | 62° | 37° | 50° | — | — |
41 years of data from ONTARIO INTL AP