S
M
T
W
T
F
S
26
86°
66°
27
87°
69°
28
75°
67°
29
78°
68°
30
80°
68°
31
80°
68°
1
82°
71°
2
77°
68°
3
80°
64°
4
80°
65°
5
82°
68°
6
82°
69°
7
85°
69°
8
83°
67°
9
82°
66°
10
78°
65°
11
77°
64°
12
76°
61°
13
75°
54°
14
77°
61°
15
72°
58°
16
71°
56°
17
71°
60°
18
72°
58°
19
70°
57°
20
71°
57°
21
71°
55°
22
70°
54°
23
70°
52°
24
69°
51°
25
69°
55°
26
70°
54°
27
69°
54°
28
68°
53°
29
69°
50°
30
68°
57°
31
73°
58°
1
73°
59°
2
72°
58°
3
72°
55°
4
67°
52°
5
68°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Montreal
Montreal's August 2026 forecast shows daily high temperatures ranging from 67° to 85°, with overnight lows between 50° and 71°. The average high for August is 74° with an average low of 59°. 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 Montreal. See also: September | October | November.
