S
M
T
W
T
F
S
30
76°
60°
31
73°
61°
1
74°
63°
2
74°
62°
3
76°
64°
4
75°
64°
5
80°
62°
6
79°
62°
7
74°
60°
8
76°
61°
9
73°
49°
10
69°
55°
11
68°
54°
12
72°
55°
13
73°
55°
14
73°
54°
15
72°
55°
16
73°
53°
17
65°
53°
18
71°
52°
19
66°
52°
20
66°
54°
21
70°
54°
22
70°
53°
23
71°
52°
24
68°
50°
25
59°
47°
26
63°
48°
27
66°
48°
28
67°
50°
29
68°
51°
30
68°
50°
1
67°
49°
2
67°
50°
3
66°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Montreal
Montreal's September 2026 forecast shows daily high temperatures ranging from 59° to 80°, with overnight lows between 47° and 64°. The average high for September is 71° with an average low of 55°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Montreal. See also: October | November | December.
