S
M
T
W
T
F
S
29
47°
33°
30
47°
33°
1
46°
32°
2
47°
31°
3
44°
31°
4
46°
30°
5
45°
30°
6
39°
28°
7
35°
22°
8
32°
19°
9
31°
23°
10
37°
26°
11
39°
29°
12
41°
28°
13
38°
27°
14
32°
22°
15
35°
23°
16
38°
26°
17
39°
25°
18
34°
20°
19
35°
18°
20
32°
14°
21
31°
14°
22
28°
18°
23
35°
23°
24
34°
20°
25
34°
11°
26
32°
10°
27
27°
8°
28
27°
8°
29
26°
11°
30
26°
18°
31
27°
13°
1
33°
9°
2
26°
7°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Wheaton
Wheaton's December 2026 forecast shows daily high temperatures ranging from 26° to 47°, with overnight lows between 7° and 33°. The average high for December is 36° with an average low of 21°. 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 Wheaton. See also: January | February | March.