S
M
T
W
T
F
S
30
89°
47°
31
88°
48°
1
87°
49°
2
89°
50°
3
88°
47°
4
80°
44°
5
81°
46°
6
82°
47°
7
79°
40°
8
77°
39°
9
77°
46°
10
78°
39°
11
76°
36°
12
75°
41°
13
76°
36°
14
74°
38°
15
75°
37°
16
75°
34°
17
72°
37°
18
74°
37°
19
76°
35°
20
74°
36°
21
77°
37°
22
79°
38°
23
80°
42°
24
72°
32°
25
Hist. Avg.
76°
42°
26
Hist. Avg.
75°
41°
27
Hist. Avg.
75°
41°
28
Hist. Avg.
75°
41°
29
Hist. Avg.
74°
40°
30
Hist. Avg.
74°
40°
1
Hist. Avg.
73°
40°
2
Hist. Avg.
73°
39°
3
Hist. Avg.
73°
39°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Charleston
Charleston's September 2026 forecast shows daily high temperatures ranging from 72° to 89°, with overnight lows between 32° and 50°. The average high for September is 79° with an average low of 41°. 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.
