S
M
T
W
T
F
S
30
92°
71°
31
91°
71°
1
90°
70°
2
92°
71°
3
92°
70°
4
91°
70°
5
91°
69°
6
90°
69°
7
91°
68°
8
91°
69°
9
92°
69°
10
92°
68°
11
91°
69°
12
92°
70°
13
91°
69°
14
89°
65°
15
90°
66°
16
89°
66°
17
90°
65°
18
87°
64°
19
88°
64°
20
87°
63°
21
88°
62°
22
87°
64°
23
84°
63°
24
84°
62°
25
83°
62°
26
84°
61°
27
85°
62°
28
86°
62°
29
84°
61°
30
84°
61°
1
83°
52°
2
78°
50°
3
74°
50°
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 74° to 92°, with overnight lows between 50° and 71°. The average high for September is 88° with an average low of 65°. 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.
