S
M
T
W
T
F
S
29
46°
26°
30
42°
20°
1
32°
12°
2
30°
12°
3
34°
25°
4
37°
25°
5
34°
24°
6
33°
18°
7
30°
15°
8
28°
18°
9
35°
18°
10
39°
23°
11
38°
23°
12
42°
22°
13
41°
23°
14
35°
20°
15
35°
20°
16
36°
18°
17
35°
12°
18
34°
9°
19
31°
5°
20
26°
5°
21
23°
17°
22
34°
18°
23
34°
11°
24
33°
4°
25
29°
17°
26
30°
19°
27
35°
18°
28
35°
16°
29
34°
12°
30
33°
11°
31
30°
1°
1
27°
0°
2
22°
10°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Decatur
Decatur's December 2026 forecast shows daily high temperatures ranging from 22° to 46°, with overnight lows between -0° and 26°. The average high for December is 33° with an average low of 16°. 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 Decatur. See also: January | February | March.
