S
M
T
W
T
F
S
30
73°
52°
31
73°
48°
1
77°
56°
2
75°
58°
3
78°
64°
4
75°
60°
5
69°
54°
6
70°
51°
7
78°
59°
8
72°
52°
9
70°
64°
10
75°
49°
11
68°
47°
12
73°
60°
13
76°
59°
14
69°
51°
15
68°
54°
16
70°
52°
17
68°
52°
18
68°
51°
19
66°
49°
20
64°
45°
21
60°
50°
22
61°
49°
23
68°
50°
24
69°
49°
25
69°
49°
26
68°
47°
27
62°
44°
28
67°
48°
29
68°
48°
30
69°
50°
1
70°
49°
2
69°
48°
3
66°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Saint-Hyacinthe
Saint-Hyacinthe's September 2026 forecast shows daily high temperatures ranging from 60° to 78°, with overnight lows between 44° and 64°. The average high for September is 69° 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-Hyacinthe. See also: October | November | December.
