Thunder Bay
Climate

Thunder Bay

Section Title: Climate
Table Section Text: None

Climate data for Thunder Bay Airport, 1981−2010 normals, extremes 1877−present

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year

Record high humidex	9.2	15.4	22.9	29.7	38.7	43.1	46.2	45.4	41.2	32.3	21.7	11.8	46.2

Record high °C (°F)	8.3 (46.9)	15.5 (59.9)	23.8 (74.8)	28.3 (82.9)	35.2 (95.4)	39.0 (102.2)	40.0 (104.0)	40.3 (104.5)	34.1 (93.4)	28.3 (82.9)	21.7 (71.1)	12.2 (54.0)	40.3 (104.5)

Average high °C (°F)	−8 (18)	−5 (23)	0.6 (33.1)	9.2 (48.6)	16.2 (61.2)	20.6 (69.1)	24.3 (75.7)	23.3 (73.9)	17.7 (63.9)	9.9 (49.8)	1.4 (34.5)	−5.5 (22.1)	8.7 (47.7)

Daily mean °C (°F)	−14.3 (6.3)	−11.3 (11.7)	−5.1 (22.8)	3.0 (37.4)	9.2 (48.6)	13.9 (57.0)	17.7 (63.9)	16.9 (62.4)	11.7 (53.1)	4.5 (40.1)	−3.2 (26.2)	−10.8 (12.6)	2.7 (36.9)

Average low °C (°F)	−20.6 (−5.1)	−17.7 (0.1)	−10.7 (12.7)	−3.2 (26.2)	2.2 (36.0)	7.1 (44.8)	11.1 (52.0)	10.4 (50.7)	5.5 (41.9)	−0.9 (30.4)	−7.7 (18.1)	−16 (3)	−3.4 (25.9)

Record low °C (°F)	−43.2 (−45.8)	−40.6 (−41.1)	−36.7 (−34.1)	−23.3 (−9.9)	−8.9 (16.0)	−3.9 (25.0)	0.0 (32.0)	−1.1 (30.0)	−8.3 (17.1)	−15.6 (3.9)	−30.6 (−23.1)	−39.6 (−39.3)	−43.2 (−45.8)

Record low wind chill	−58.2	−54.0	−42.7	−32.0	−16.2	−5.8	0.0	−4.0	−10.8	−20.6	−40.0	−51.0	−58.2

Average precipitation mm (inches)	26.3 (1.04)	20.5 (0.81)	31.3 (1.23)	52.9 (2.08)	67.0 (2.64)	83.5 (3.29)	87.0 (3.43)	89.5 (3.52)	73.1 (2.88)	64.3 (2.53)	53.1 (2.09)	35.2 (1.39)	683.7 (26.92)

Average rainfall mm (inches)	0.39 (0.02)	2.9 (0.11)	16.1 (0.63)	36.6 (1.44)	66.3 (2.61)	83.5 (3.29)	87.0 (3.43)	89.5 (3.52)	72.0 (2.83)	55.3 (2.18)	30.7 (1.21)	6.2 (0.24)	546.5 (21.52)

Average snowfall cm (inches)	36.5 (14.4)	21.2 (8.3)	18.2 (7.2)	10.3 (4.1)	1.0 (0.4)	0.0 (0.0)	0.0 (0.0)	0.0 (0.0)	1.1 (0.4)	9.4 (3.7)	26.5 (10.4)	38.9 (15.3)	162.9 (64.1)

Average precipitation days (≥ 0.2 mm)	12.0	9.5	10.3	9.5	11.5	13.8	12.9	12.3	13.7	12.9	12.1	12.4	142.9

Average rainy days (≥ 0.2 mm)	0.57	1.1	3.4	7.1	11.0	13.8	12.9	12.3	13.5	11.0	4.7	1.2	90.7

Average snowy days (≥ 0.2 cm)	12.9	9.6	8.4	4.0	0.50	0.0	0.0	0.0	0.27	3.4	9.7	13.9	62.5

Mean monthly sunshine hours	109.6	126.7	159.8	213.0	259.0	262.0	268.1	255.9	163.8	125.4	86.2	91.2	2,120.5

Percent possible sunshine	40.1	44.2	43.4	52.0	55.0	54.5	55.2	57.6	43.2	37.2	31.0	35.0	45.7

Source #1: Environment Canada Extremes 1877–1941

Source #2: CBC

Sentence(s)

The highest temperature recorded in Thunder Bay was 40.3 °C (104.5 °F) in August.

final_sentence: The highest temperature recorded in Thunder Bay was 40.3 °C (104.5 °F) in August.