S
M
T
W
T
F
S
30
77°
52°
31
76°
51°
1
73°
58°
2
73°
50°
3
74°
49°
4
72°
57°
5
73°
59°
6
80°
54°
7
79°
50°
8
72°
49°
9
71°
53°
10
70°
55°
11
71°
53°
12
69°
54°
13
76°
54°
14
69°
44°
15
69°
44°
16
Hist. Avg.
74°
50°
17
Hist. Avg.
74°
50°
18
Hist. Avg.
73°
49°
19
Hist. Avg.
73°
49°
20
Hist. Avg.
72°
48°
21
Hist. Avg.
72°
48°
22
Hist. Avg.
72°
47°
23
Hist. Avg.
71°
47°
24
Hist. Avg.
71°
46°
25
Hist. Avg.
70°
46°
26
Hist. Avg.
70°
46°
27
Hist. Avg.
69°
45°
28
Hist. Avg.
69°
45°
29
Hist. Avg.
68°
44°
30
Hist. Avg.
68°
44°
1
Hist. Avg.
67°
43°
2
Hist. Avg.
67°
43°
3
Hist. Avg.
66°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in St. Clair
St. Clair's September 2026 forecast shows daily high temperatures ranging from 69° to 80°, with overnight lows between 44° and 59°. The average high for September is 73° with an average low of 52°. 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 St. Clair. See also: October | November | December.
