Ontario Weather in December
Average highs run from 43°F on December 1 to 35°F on December 31, and lows from 28°F to 20°F. Normal precipitation for the month is 3.11 in over about 20 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
- 39°F
- Average low
- 24°F
- Precipitation
- 3.11 in
- Snowfall
- 19.3 in
- Record high
- 70°FDec 4, 1941
- Record low
- -20°FDec 20, 1942
- Chance of a freeze
- 100%
- Daylight
- 9 h 14 min to 9 h 02 min
- Cloud cover
- 82%
- Humidity
- 88%
- Dew point
- 26°F
- Wind
- 7.4 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 | 43°F | 28°F | 68°F 1991 | 6°F 1976 | 57% | 29% |
| Dec 2 | 43°F | 28°F | 63°F 1982 | 6°F 1989 | 57% | 30% |
| Dec 3 | 43°F | 27°F | 63°F 1982 | 3°F 1976 | 58% | 31% |
| Dec 4 | 42°F | 27°F | 70°F 1941 | 0°F 1940 | 58% | 31% |
| Dec 5 | 42°F | 27°F | 69°F 2012 | 0°F 1926 | 59% | 32% |
| Dec 6 | 41°F | 26°F | 70°F 1998 | 5°F 2025 | 59% | 33% |
| Dec 7 | 41°F | 26°F | 70°F 1998 | 1°F 1926 | 60% | 34% |
| Dec 8 | 41°F | 26°F | 66°F 1966 | 4°F 1976 | 60% | 34% |
| Dec 9 | 40°F | 26°F | 62°F 1946 | -1°F 2025 | 60% | 35% |
| Dec 10 | 40°F | 25°F | 61°F 1946 | -1°F 2025 | 61% | 36% |
| Dec 11 | 40°F | 25°F | 62°F 1979 | -5°F 1960 | 61% | 37% |
| Dec 12 | 39°F | 25°F | 62°F 2015 | -4°F 1929 | 61% | 37% |
| Dec 13 | 39°F | 25°F | 58°F 1923 | -1°F 1988 | 62% | 38% |
| Dec 14 | 39°F | 24°F | 57°F 2015 | 2°F 1989 | 62% | 38% |
| Dec 15 | 39°F | 24°F | 66°F 2015 | 0°F 1943 | 62% | 39% |
| Dec 16 | 38°F | 24°F | 58°F 1971 | 0°F 1961 | 63% | 40% |
| Dec 17 | 38°F | 24°F | 67°F 2021 | -8°F 2013 | 63% | 40% |
| Dec 18 | 38°F | 23°F | 52°F 2006 | 4°F 2017 | 63% | 40% |
| Dec 19 | 37°F | 23°F | 58°F 1957 | -2°F 1951 | 63% | 41% |
| Dec 20 | 37°F | 23°F | 62°F 1957 | -20°F 1942 | 63% | 41% |
| Dec 21 | 37°F | 22°F | 61°F 1957 | -8°F 1962 | 62% | 42% |
| Dec 22 | 37°F | 22°F | 67°F 1949 | -5°F 1983 | 62% | 42% |
| Dec 23 | 36°F | 22°F | 62°F 1949 | -10°F 1955 | 62% | 43% |
| Dec 24 | 36°F | 22°F | 63°F 2015 | -12°F 1960 | 62% | 43% |
| Dec 25 | 36°F | 21°F | 66°F 2015 | -9°F 1980 | 62% | 43% |
| Dec 26 | 36°F | 21°F | 65°F 1982 | -5°F 1968 | 62% | 44% |
| Dec 27 | 36°F | 21°F | 56°F 1940 | -7°F 1993 | 62% | 44% |
| Dec 28 | 35°F | 21°F | 65°F 1949 | -8°F 1960 | 62% | 45% |
| Dec 29 | 35°F | 21°F | 64°F 1984 | -6°F 1993 | 62% | 45% |
| Dec 30 | 35°F | 20°F | 61°F 2024 | -1°F 1962 | 62% | 46% |
| Dec 31 | 35°F | 20°F | 63°F 1965 | 0°F 1983 | 62% | 46% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (EST).
- December 1
- sunrise 7:21 AM, sunset 4:35 PM
- December 31
- sunrise 7:41 AM, sunset 4:43 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00309049 (Webster 2 Ne), public domain. Records: NOAA GHCN-Daily, station USC00307842, 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.