S
M
T
W
T
F
S
30
79°
58°
31
78°
51°
1
77°
47°
2
70°
48°
3
69°
54°
4
73°
57°
5
75°
55°
6
77°
47°
7
69°
47°
8
71°
51°
9
74°
51°
10
66°
54°
11
74°
54°
12
73°
53°
13
72°
52°
14
65°
47°
15
64°
44°
16
63°
43°
17
63°
51°
18
66°
43°
19
63°
53°
20
68°
52°
21
70°
45°
22
64°
41°
23
60°
43°
24
61°
42°
25
58°
40°
26
58°
41°
27
Hist. Avg.
64°
44°
28
Hist. Avg.
64°
44°
29
Hist. Avg.
64°
43°
30
Hist. Avg.
63°
43°
1
Hist. Avg.
63°
43°
2
Hist. Avg.
62°
42°
3
Hist. Avg.
62°
42°
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 58° to 79°, with overnight lows between 40° and 58°. The average high for September is 69° with an average low of 49°. 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.
