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Thunder Bay December Weather

Averages and records for weather in Thunder Bay, Ontario in the month of December.

Typical Thunder Bay December Weather 1991–2020
Average daily high	-4.4 °C
Average daily low	-14.5 °C
Average monthly precipitation	2.7 cm
Daily chance of precipitation	38.8%

Thunder Bay December Weather Records 1941–2024
Highest temperature	13.7 °C	December 14, 2023
Lowest temperature	-39.6 °C	December 31, 2013
Highest daily low	3.9 °C	December 1, 1962
Lowest daily high	-26.1 °C	December 31, 1967
Hottest average high temperature	2.4 °C	2023
Coldest average high temperature	-11.7 °C	1989
Most daily precipitation	4.3 cm	December 5, 1948
Most monthly precipitation	10.6 cm	1948

Note: Daily averages are a moving average which includes 14 days before and after

Day	Average (°C)		Record (°C)
Day	High	Low	High	Low
December 1	-1.6	-11.3	11.1	-32.5
December 2	-1.8	-11.5	11.7	-31.6
December 3	-2.1	-11.8	12.2	-32.2
December 4	-2.3	-12.1	11.1	-31.7
December 5	-2.5	-12.3	10.0	-28.6
December 6	-2.7	-12.5	8.1	-28.9
December 7	-2.8	-12.6	3.9	-29.0
December 8	-3.0	-12.8	6.4	-35.0
December 9	-3.2	-13.0	8.5	-34.4
December 10	-3.4	-13.2	5.6	-33.0
December 11	-3.6	-13.4	8.3	-37.3
December 12	-3.7	-13.7	6.7	-31.2
December 13	-3.9	-14.0	6.7	-37.8
December 14	-4.1	-14.3	13.7	-31.7
December 15	-4.3	-14.5	9.7	-29.1
December 16	-4.5	-14.6	10.4	-33.9
December 17	-4.7	-14.8	5.0	-27.6
December 18	-5.0	-15.1	5.8	-33.3
December 19	-5.2	-15.4	5.2	-33.3
December 20	-5.3	-15.5	5.7	-33.3
December 21	-5.4	-15.7	9.0	-31.1
December 22	-5.5	-15.8	5.7	-28.2
December 23	-5.7	-16.0	4.0	-32.4
December 24	-5.8	-16.1	8.3	-33.4
December 25	-5.9	-16.3	7.9	-34.9
December 26	-5.9	-16.4	6.0	-33.4
December 27	-6.0	-16.5	5.7	-32.8
December 28	-6.1	-16.6	7.3	-31.0
December 29	-6.3	-16.8	4.8	-31.7
December 30	-6.4	-17.1	4.4	-36.7
December 31	-6.6	-17.3	2.2	-39.6

Weather Station Details

Years	Station	Coordinates
2004–2024	Thunder Bay CS	location
1941–2003	Thunder Bay A	location