S
M
T
W
T
F
S
29
49°
41°
30
60°
41°
1
58°
42°
2
61°
39°
3
48°
36°
4
54°
34°
5
57°
40°
6
57°
35°
7
47°
34°
8
46°
29°
9
46°
30°
10
45°
26°
11
44°
26°
12
44°
27°
13
46°
26°
14
46°
26°
15
47°
32°
16
47°
37°
17
48°
38°
18
54°
32°
19
53°
25°
20
46°
24°
21
44°
24°
22
44°
26°
23
46°
29°
24
44°
26°
25
44°
25°
26
42°
24°
27
43°
25°
28
43°
24°
29
44°
29°
30
48°
30°
31
52°
25°
1
47°
21°
2
42°
20°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Charleston
Charleston's December 2026 forecast shows daily high temperatures ranging from 42° to 61°, with overnight lows between 20° and 42°. The average high for December is 48° with an average low of 30°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how December weather will actually feel in Charleston. See also: January | February | March.