S
M
T
W
T
F
S
30
76°
55°
31
75°
47°
1
69°
46°
2
67°
52°
3
68°
54°
4
75°
48°
5
75°
44°
6
70°
45°
7
68°
45°
8
68°
53°
9
70°
51°
10
66°
46°
11
65°
48°
12
65°
45°
13
66°
42°
14
62°
42°
15
63°
46°
16
63°
51°
17
64°
50°
18
68°
51°
19
68°
47°
20
69°
48°
21
66°
44°
22
61°
42°
23
59°
40°
24
60°
39°
25
60°
42°
26
59°
39°
27
67°
47°
28
59°
47°
29
65°
40°
30
Hist. Avg.
61°
41°
1
Hist. Avg.
60°
40°
2
Hist. Avg.
60°
40°
3
Hist. Avg.
59°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Montreal
Montreal's September 2026 forecast shows daily high temperatures ranging from 59° to 76°, with overnight lows between 39° and 55°. The average high for September is 66° with an average low of 46°. 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.
