S
M
T
W
T
F
S
30
83°
62°
31
82°
66°
1
86°
64°
2
82°
57°
3
80°
55°
4
79°
56°
5
80°
56°
6
81°
57°
7
84°
59°
8
85°
64°
9
86°
61°
10
85°
55°
11
80°
60°
12
82°
61°
13
82°
53°
14
78°
52°
15
78°
52°
16
77°
53°
17
78°
57°
18
81°
55°
19
81°
59°
20
82°
58°
21
83°
58°
22
82°
59°
23
81°
59°
24
77°
58°
25
79°
57°
26
81°
57°
27
82°
56°
28
82°
56°
29
81°
55°
30
82°
56°
1
81°
56°
2
81°
47°
3
80°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in St. Clair
St. Clair's September 2026 forecast shows daily high temperatures ranging from 77° to 86°, with overnight lows between 46° and 66°. The average high for September is 81° with an average low of 57°. 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.
