S
M
T
W
T
F
S
30
69°
50°
31
65°
50°
1
69°
57°
2
62°
55°
3
65°
56°
4
64°
56°
5
65°
53°
6
66°
55°
7
68°
51°
8
73°
50°
9
74°
51°
10
65°
55°
11
63°
51°
12
59°
54°
13
66°
53°
14
68°
51°
15
65°
49°
16
71°
51°
17
62°
52°
18
62°
57°
19
63°
56°
20
63°
56°
21
64°
55°
22
66°
49°
23
68°
50°
24
64°
52°
25
65°
48°
26
66°
49°
27
65°
51°
28
65°
50°
29
64°
54°
30
65°
50°
1
66°
51°
2
55°
50°
3
61°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Charleston
Charleston's September 2026 forecast shows daily high temperatures ranging from 55° to 68°, with overnight lows between 48° and 56°. The average high for September is 64° 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 Charleston. See also: October | November | December.
