S
M
T
W
T
F
S
30
85°
66°
31
89°
66°
1
91°
65°
2
92°
66°
3
91°
66°
4
91°
67°
5
90°
68°
6
87°
66°
7
75°
65°
8
81°
61°
9
86°
58°
10
89°
60°
11
90°
62°
12
80°
68°
13
85°
65°
14
88°
61°
15
78°
64°
16
87°
65°
17
89°
65°
18
91°
63°
19
86°
65°
20
86°
64°
21
87°
63°
22
80°
65°
23
68°
59°
24
63°
52°
25
76°
45°
26
76°
46°
27
76°
44°
28
75°
49°
29
78°
52°
30
78°
60°
1
77°
61°
2
74°
56°
3
73°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Flat Rock
Flat Rock's September 2026 forecast shows daily high temperatures ranging from 63° to 78°, with overnight lows between 44° and 61°. The average high for September is 75° 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 Flat Rock. See also: October | November | December.
