Ontario Weather in December
Average highs run from 40°F on December 1 to 35°F on December 31, and lows from 24°F to 22°F. Normal precipitation for the month is 1.58 in over about 11 wet days.
December day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 36°F
- Average low
- 22°F
- Precipitation
- 1.58 in
- Snowfall
- 5.4 in
- Record high
- 60°FDec 5, 2012
- Record low
- -14°FDec 9, 2013
- Chance of a freeze
- 100%
- Daylight
- 9 h 08 min to 8 h 56 min
- Cloud cover
- 68%
- Humidity
- 77%
- Dew point
- 24°F
- Wind
- 6.3 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Dec 1 | 40°F | 24°F | 54°F 2012 | 14°F 2006 | 32% | 8% |
| Dec 2 | 40°F | 24°F | 58°F 2012 | 15°F 2006 | 32% | 8% |
| Dec 3 | 39°F | 24°F | 55°F 2003 | 12°F 2006 | 32% | 9% |
| Dec 4 | 39°F | 24°F | 58°F 2007 | 10°F 2005 | 32% | 9% |
| Dec 5 | 39°F | 24°F | 60°F 2012 | 5°F 2005 | 33% | 9% |
| Dec 6 | 38°F | 23°F | 56°F 2025 | 7°F 2013 | 33% | 9% |
| Dec 7 | 38°F | 23°F | 51°F 2023 | 6°F 2013 | 33% | 10% |
| Dec 8 | 38°F | 23°F | 54°F 2015 | -12°F 2013 | 33% | 10% |
| Dec 9 | 37°F | 23°F | 55°F 2015 | -14°F 2013 | 33% | 10% |
| Dec 10 | 37°F | 23°F | 53°F 2015 | -3°F 2009 | 33% | 10% |
| Dec 11 | 37°F | 23°F | 56°F 2014 | -2°F 2009 | 33% | 10% |
| Dec 12 | 37°F | 22°F | 56°F 2014 | -1°F 2013 | 34% | 11% |
| Dec 13 | 36°F | 22°F | 55°F 2002 | 7°F 2005 | 34% | 11% |
| Dec 14 | 36°F | 22°F | 57°F 2002 | 1°F 2005 | 34% | 11% |
| Dec 15 | 36°F | 22°F | 56°F 2002 | 1°F 2005 | 34% | 11% |
| Dec 16 | 36°F | 22°F | 55°F 2002 | 0°F 2005 | 34% | 12% |
| Dec 17 | 36°F | 22°F | 58°F 2025 | -4°F 2016 | 34% | 12% |
| Dec 18 | 35°F | 22°F | 50°F 1999 | -11°F 2016 | 34% | 12% |
| Dec 19 | 35°F | 22°F | 53°F 2025 | -5°F 2016 | 34% | 12% |
| Dec 20 | 35°F | 22°F | 46°F 2024 | 5°F 2008 | 34% | 12% |
| Dec 21 | 35°F | 22°F | 50°F 2014 | -1°F 1998 | 34% | 13% |
| Dec 22 | 35°F | 22°F | 51°F 2014 | -1°F 1998 | 34% | 13% |
| Dec 23 | 35°F | 22°F | 50°F 2021 | -1°F 1998 | 34% | 13% |
| Dec 24 | 35°F | 22°F | 54°F 2024 | 6°F 2011 | 34% | 13% |
| Dec 25 | 35°F | 21°F | 54°F 2025 | 4°F 2013 | 34% | 13% |
| Dec 26 | 35°F | 21°F | 54°F 2025 | -6°F 2016 | 34% | 13% |
| Dec 27 | 35°F | 21°F | 53°F 2002 | 5°F 2016 | 34% | 13% |
| Dec 28 | 35°F | 22°F | 51°F 2002 | 6°F 2013 | 33% | 13% |
| Dec 29 | 35°F | 22°F | 53°F 2011 | 1°F 2016 | 33% | 14% |
| Dec 30 | 35°F | 22°F | 56°F 2011 | -7°F 2016 | 33% | 14% |
| Dec 31 | 35°F | 22°F | 48°F 2002 | -9°F 2016 | 33% | 14% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MST).
- December 1
- sunrise 8:03 AM, sunset 5:11 PM
- December 31
- sunrise 8:23 AM, sunset 5:19 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00356294 (Ontario Ksrv), public domain. Records: NOAA GHCN-Daily, station USW00024162, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.