S
M
T
W
T
F
S
26
76°
55°
27
76°
54°
28
82°
51°
29
88°
54°
30
76°
61°
31
86°
63°
1
80°
56°
2
76°
49°
3
80°
49°
4
75°
54°
5
76°
45°
6
83°
48°
7
78°
55°
8
78°
55°
9
79°
54°
10
80°
51°
11
78°
55°
12
78°
57°
13
80°
52°
14
76°
46°
15
64°
52°
16
77°
53°
17
81°
49°
18
74°
48°
19
74°
44°
20
63°
44°
21
73°
57°
22
74°
49°
23
68°
45°
24
75°
42°
25
66°
46°
26
78°
58°
27
74°
48°
28
73°
42°
29
74°
42°
30
72°
57°
31
65°
61°
1
82°
57°
2
78°
52°
3
74°
49°
4
69°
58°
5
77°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Thunder Bay
Thunder Bay's August 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for August is ° with an average low of °. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Thunder Bay. See also: September | October | November.
