S
M
T
W
T
F
S
29
55°
38°
30
58°
44°
1
56°
40°
2
57°
38°
3
61°
39°
4
64°
42°
5
61°
38°
6
53°
39°
7
58°
44°
8
65°
43°
9
61°
42°
10
62°
44°
11
62°
42°
12
61°
37°
13
52°
35°
14
55°
29°
15
49°
30°
16
49°
29°
17
50°
29°
18
52°
42°
19
63°
43°
20
62°
41°
21
55°
35°
22
52°
31°
23
59°
42°
24
62°
40°
25
49°
30°
26
50°
29°
27
49°
36°
28
51°
30°
29
60°
30°
30
51°
31°
31
51°
29°
1
50°
28°
2
50°
29°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Sumter
Sumter's December 2026 forecast shows daily high temperatures ranging from 49° to 65°, with overnight lows between 28° and 44°. The average high for December is 56° with an average low of 36°. 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 Sumter. See also: January | February | March.
