Thunder Bay Average Weather by Day

Data and chart of the the average high and low temperature for every day of the year in Thunder Bay, Ontario, based on NOAA data.

Also see:

What's the hottest day of the year in Thunder Bay?

On average, July 26 is the hottest day of the year Thunder Bay, Ontario. From 1991–2020, the average high temperature on July 26 was 24.9 °C and the average low was 11.3 °C.

What's the coldest day of the year in Thunder Bay?

On average, January 16 is the coldest day of the year Thunder Bay, Ontario. From 1991–2020, the average high temperature on January 16 was -7.8 °C, and the average low was -19.5 °C.

Average Temperature by Day

Average temperatures from 1991–2020. Daily averages are a mean of the period from 14 days before to 14 days after, inclusive.

Day	Average (°C)
Day	High	Low
January 1	-6.7	-17.4
January 2	-6.8	-17.6
January 3	-6.8	-17.7
January 4	-7.0	-17.9
January 5	-7.3	-18.2
January 6	-7.4	-18.5
January 7	-7.5	-18.7
January 8	-7.5	-18.8
January 9	-7.6	-18.9
January 10	-7.6	-18.9
January 11	-7.8	-19.1
January 12	-7.8	-19.1
January 13	-7.8	-19.1
January 14	-7.8	-19.3
January 15	-7.8	-19.4
January 16	-7.8	-19.5
January 17	-7.8	-19.5
January 18	-7.8	-19.5
January 19	-7.8	-19.5
January 20	-7.7	-19.5
January 21	-7.6	-19.5
January 22	-7.6	-19.6
January 23	-7.6	-19.6
January 24	-7.6	-19.6
January 25	-7.6	-19.7
January 26	-7.6	-19.7
January 27	-7.5	-19.8
January 28	-7.5	-19.8
January 29	-7.4	-19.8
January 30	-7.4	-19.9
January 31	-7.3	-19.9
February 1	-7.3	-20.0
February 2	-7.2	-20.0
February 3	-7.0	-19.8
February 4	-6.8	-19.6
February 5	-6.6	-19.4
February 6	-6.5	-19.3
February 7	-6.4	-19.3
February 8	-6.2	-19.3
February 9	-6.0	-19.0
February 10	-5.9	-18.9
February 11	-5.8	-18.8
February 12	-5.6	-18.7
February 13	-5.5	-18.5
February 14	-5.3	-18.4
February 15	-5.2	-18.4
February 16	-5.1	-18.3
February 17	-4.9	-18.2
February 18	-4.8	-18.2
February 19	-4.7	-18.1
February 20	-4.6	-17.9
February 21	-4.4	-17.8
February 22	-4.2	-17.6
February 23	-4.1	-17.4
February 24	-3.8	-17.2
February 25	-3.6	-17.0
February 26	-3.3	-16.7
February 27	-3.0	-16.3
February 28	-2.7	-16.0
March 1	-2.5	-15.7
March 2	-2.2	-15.5
March 3	-1.9	-15.1
March 4	-1.7	-14.8
March 5	-1.5	-14.5
March 6	-1.3	-14.3
March 7	-1.1	-14.1
March 8	-0.8	-13.8
March 9	-0.6	-13.5
March 10	-0.4	-13.3
March 11	-0.2	-13.0
March 12	0.0	-12.8
March 13	0.3	-12.4
March 14	0.6	-12.1
March 15	0.9	-11.7
March 16	1.1	-11.4
March 17	1.4	-11.0
March 18	1.7	-10.6
March 19	2.0	-10.2
March 20	2.3	-9.8
March 21	2.5	-9.5
March 22	2.8	-9.2
March 23	3.1	-8.9
March 24	3.3	-8.7
March 25	3.5	-8.4
March 26	3.8	-8.2
March 27	4.0	-7.9
March 28	4.2	-7.7
March 29	4.4	-7.4
March 30	4.7	-7.2
March 31	4.9	-6.9
April 1	5.2	-6.6
April 2	5.4	-6.4
April 3	5.6	-6.3
April 4	5.9	-6.0
April 5	6.1	-5.8
April 6	6.4	-5.5
April 7	6.7	-5.4
April 8	6.9	-5.2
April 9	7.3	-5.0
April 10	7.5	-4.8
April 11	7.7	-4.6
April 12	7.9	-4.5
April 13	8.1	-4.4
April 14	8.3	-4.3
April 15	8.6	-4.2
April 16	8.9	-4.0
April 17	9.1	-3.8
April 18	9.4	-3.6
April 19	9.7	-3.5
April 20	10.0	-3.2
April 21	10.3	-3.0
April 22	10.6	-2.8
April 23	10.9	-2.6
April 24	11.1	-2.4
April 25	11.3	-2.2
April 26	11.5	-2.0
April 27	11.7	-1.9
April 28	11.9	-1.7
April 29	12.1	-1.5
April 30	12.3	-1.3
May 1	12.5	-1.1
May 2	12.7	-0.9
May 3	12.9	-0.8
May 4	13.2	-0.7
May 5	13.4	-0.5
May 6	13.7	-0.3
May 7	13.9	-0.1
May 8	14.1	0.2
May 9	14.3	0.4
May 10	14.6	0.6
May 11	14.8	0.9
May 12	15.1	1.2
May 13	15.4	1.4
May 14	15.6	1.6
May 15	15.9	1.8
May 16	16.1	2.0
May 17	16.3	2.2
May 18	16.4	2.4
May 19	16.6	2.6
May 20	16.8	2.8
May 21	16.9	2.9
May 22	17.1	3.1
May 23	17.3	3.3
May 24	17.6	3.4
May 25	17.8	3.6
May 26	18.0	3.8
May 27	18.2	4.0
May 28	18.4	4.2
May 29	18.6	4.4
May 30	18.8	4.6
May 31	19.0	4.8
June 1	19.1	5.0
June 2	19.3	5.2
June 3	19.5	5.5
June 4	19.7	5.7
June 5	19.8	5.9
June 6	20.1	6.1
June 7	20.2	6.2
June 8	20.4	6.4
June 9	20.5	6.5
June 10	20.7	6.7
June 11	20.8	6.9
June 12	21.0	7.1
June 13	21.1	7.3
June 14	21.2	7.4
June 15	21.3	7.6
June 16	21.5	7.8
June 17	21.6	8.0
June 18	21.7	8.1
June 19	21.9	8.3
June 20	22.0	8.5
June 21	22.2	8.6
June 22	22.4	8.8
June 23	22.4	9.0
June 24	22.6	9.1
June 25	22.7	9.2
June 26	22.9	9.3
June 27	23.0	9.5
June 28	23.1	9.6
June 29	23.2	9.8
June 30	23.4	9.9
July 1	23.5	10.0
July 2	23.6	10.1
July 3	23.7	10.3
July 4	23.7	10.4
July 5	23.8	10.4
July 6	23.8	10.5
July 7	24.0	10.6
July 8	24.1	10.7
July 9	24.2	10.7
July 10	24.2	10.8
July 11	24.2	10.9
July 12	24.3	10.9
July 13	24.3	11.0
July 14	24.4	11.0
July 15	24.5	11.0
July 16	24.6	11.1
July 17	24.7	11.1
July 18	24.8	11.2
July 19	24.8	11.2
July 20	24.8	11.2
July 21	24.8	11.2
July 22	24.9	11.2
July 23	24.9	11.2
July 24	24.9	11.2
July 25	24.9	11.2
July 26	24.9	11.3
July 27	24.9	11.2
July 28	24.9	11.1
July 29	24.9	11.0
July 30	24.9	11.0
July 31	24.8	10.9
August 1	24.8	10.8
August 2	24.8	10.8
August 3	24.8	10.8
August 4	24.7	10.7
August 5	24.6	10.6
August 6	24.6	10.6
August 7	24.5	10.5
August 8	24.5	10.5
August 9	24.4	10.4
August 10	24.4	10.3
August 11	24.4	10.3
August 12	24.4	10.3
August 13	24.3	10.3
August 14	24.2	10.2
August 15	24.1	10.1
August 16	23.9	10.0
August 17	23.8	9.9
August 18	23.8	9.8
August 19	23.7	9.8
August 20	23.6	9.7
August 21	23.4	9.6
August 22	23.3	9.5
August 23	23.2	9.4
August 24	23.1	9.3
August 25	22.9	9.2
August 26	22.7	9.0
August 27	22.5	8.9
August 28	22.4	8.8
August 29	22.3	8.7
August 30	22.1	8.6
August 31	21.9	8.4
September 1	21.8	8.2
September 2	21.7	8.1
September 3	21.6	8.0
September 4	21.4	7.9
September 5	21.2	7.7
September 6	21.0	7.5
September 7	20.8	7.4
September 8	20.6	7.2
September 9	20.3	6.9
September 10	20.1	6.6
September 11	19.9	6.5
September 12	19.7	6.3
September 13	19.5	6.1
September 14	19.2	5.9
September 15	19.0	5.7
September 16	18.7	5.5
September 17	18.4	5.2
September 18	18.2	4.9
September 19	17.9	4.7
September 20	17.6	4.5
September 21	17.3	4.2
September 22	17.1	4.1
September 23	16.8	3.9
September 24	16.6	3.7
September 25	16.4	3.6
September 26	16.2	3.4
September 27	16.0	3.2
September 28	15.8	3.0
September 29	15.5	2.8
September 30	15.2	2.7
October 1	14.9	2.4
October 2	14.6	2.2
October 3	14.3	2.0
October 4	14.0	1.8
October 5	13.8	1.6
October 6	13.5	1.4
October 7	13.2	1.2
October 8	12.9	1.1
October 9	12.6	0.9
October 10	12.3	0.7
October 11	12.0	0.5
October 12	11.7	0.3
October 13	11.5	0.1
October 14	11.2	0.0
October 15	10.9	-0.1
October 16	10.7	-0.3
October 17	10.4	-0.4
October 18	10.2	-0.6
October 19	9.9	-0.6
October 20	9.7	-0.8
October 21	9.4	-1.0
October 22	9.2	-1.2
October 23	8.9	-1.3
October 24	8.6	-1.6
October 25	8.3	-1.8
October 26	8.0	-2.0
October 27	7.6	-2.2
October 28	7.3	-2.5
October 29	7.1	-2.7
October 30	6.9	-2.9
October 31	6.6	-3.0
November 1	6.4	-3.2
November 2	6.1	-3.5
November 3	5.8	-3.7
November 4	5.6	-3.9
November 5	5.3	-4.1
November 6	5.0	-4.3
November 7	4.8	-4.7
November 8	4.5	-4.9
November 9	4.2	-5.2
November 10	3.9	-5.4
November 11	3.7	-5.7
November 12	3.4	-6.0
November 13	3.1	-6.3
November 14	2.8	-6.5
November 15	2.6	-6.7
November 16	2.3	-7.0
November 17	2.0	-7.4
November 18	1.8	-7.7
November 19	1.6	-7.9
November 20	1.3	-8.1
November 21	1.0	-8.5
November 22	0.7	-8.8
November 23	0.4	-9.1
November 24	0.0	-9.5
November 25	-0.2	-9.8
November 26	-0.5	-10.0
November 27	-0.7	-10.3
November 28	-1.0	-10.7
November 29	-1.2	-10.9
November 30	-1.4	-11.1
December 1	-1.6	-11.3
December 2	-1.8	-11.5
December 3	-2.1	-11.8
December 4	-2.3	-12.1
December 5	-2.5	-12.3
December 6	-2.7	-12.5
December 7	-2.8	-12.6
December 8	-3.0	-12.8
December 9	-3.2	-13.0
December 10	-3.4	-13.2
December 11	-3.6	-13.4
December 12	-3.7	-13.7
December 13	-3.9	-14.0
December 14	-4.1	-14.3
December 15	-4.3	-14.5
December 16	-4.5	-14.6
December 17	-4.7	-14.8
December 18	-5.0	-15.1
December 19	-5.2	-15.4
December 20	-5.3	-15.5
December 21	-5.4	-15.7
December 22	-5.5	-15.8
December 23	-5.7	-16.0
December 24	-5.8	-16.1
December 25	-5.9	-16.3
December 26	-5.9	-16.4
December 27	-6.0	-16.5
December 28	-6.1	-16.6
December 29	-6.3	-16.8
December 30	-6.4	-17.1
December 31	-6.6	-17.3

Weather Station Details

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