Cornwall December Weather

Averages and records for weather in Cornwall, Ontario in the month of December.
Typical Cornwall December Weather
1991–2020
Average daily high 0.0 °C
Average daily low -6.7 °C
Average monthly precipitation 7.5 cm
Average monthly snow 39.4 cm
Daily chance of precipitation 45.8%
Daily chance of snow 30.2%
Cornwall December Weather Records
1867–2024
Highest temperature 20.0 °C December 5, 2001
Lowest temperature -34.4 °C December 21, 1879
Highest daily low 10.0 °C December 20, 1957
Lowest daily high -22.8 °C December 20, 1884
Hottest average high temperature 5.7 °C 2015
Coldest average high temperature -10.1 °C 1989
Most daily precipitation 3.6 cm December 21, 1993
Most monthly precipitation 17.0 cm 1973
Most daily snow 35.5 cm December 21, 1993
Most monthly snow 117.6 cm 1972
Note: Daily averages are a moving average which includes 14 days before and after
Day Average (°C) Record (°C)
High Low High Low
December 1 3.0 -3.6 18.0 -30.0
December 2 2.8 -3.8 11.5 -21.7
December 3 2.6 -4.0 18.0 -23.3
December 4 2.3 -4.2 19.0 -23.9
December 5 2.0 -4.5 20.0 -28.3
December 6 1.8 -4.8 18.0 -23.9
December 7 1.6 -5.0 17.8 -20.6
December 8 1.5 -5.2 17.8 -22.0
December 9 1.3 -5.2 16.1 -25.0
December 10 1.1 -5.4 12.8 -23.9
December 11 0.9 -5.6 15.0 -25.0
December 12 0.7 -5.9 13.0 -27.8
December 13 0.5 -6.1 12.5 -27.8
December 14 0.3 -6.3 13.9 -27.2
December 15 0.1 -6.6 12.2 -23.3
December 16 -0.2 -6.9 17.5 -26.1
December 17 -0.4 -7.1 14.5 -31.7
December 18 -0.6 -7.3 8.0 -29.4
December 19 -0.9 -7.6 11.7 -30.0
December 20 -1.0 -7.9 16.7 -30.0
December 21 -1.1 -8.1 13.3 -34.4
December 22 -1.2 -8.3 11.7 -33.3
December 23 -1.3 -8.3 18.5 -32.2
December 24 -1.4 -8.4 19.0 -28.9
December 25 -1.6 -8.6 16.0 -33.9
December 26 -1.7 -8.8 11.7 -32.8
December 27 -1.8 -8.9 15.0 -29.5
December 28 -1.9 -9.0 16.5 -33.3
December 29 -1.9 -9.1 12.0 -28.9
December 30 -2.0 -9.2 12.5 -30.6
December 31 -2.2 -9.4 14.4 -32.2
Weather Station Details
Years Station Coordinates
1950–2024 Cornwall location
1867–1887 Cornwall location