S
M
T
W
T
F
S
30
74°
51°
31
75°
49°
1
76°
55°
2
76°
59°
3
80°
63°
4
74°
58°
5
70°
53°
6
72°
51°
7
79°
52°
8
72°
53°
9
71°
53°
10
73°
51°
11
66°
47°
12
75°
45°
13
76°
61°
14
65°
43°
15
65°
40°
16
76°
56°
17
69°
52°
18
69°
41°
19
63°
37°
20
61°
44°
21
60°
43°
22
64°
39°
23
67°
39°
24
70°
41°
25
73°
48°
26
69°
52°
27
64°
52°
28
63°
51°
29
62°
48°
30
70°
57°
1
69°
55°
2
70°
51°
3
68°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Saint-Jean-sur-Richelieu
Saint-Jean-sur-Richelieu's September 2026 forecast shows daily high temperatures ranging from 62° to 73°, with overnight lows between 41° and 57°. The average high for September is 68° with an average low of 51°. 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 Saint-Jean-sur-Richelieu. See also: October | November | December.
