S
M
T
W
T
F
S
29
40°
32°
30
36°
29°
1
36°
35°
2
45°
35°
3
45°
37°
4
47°
38°
5
46°
36°
6
45°
36°
7
37°
23°
8
35°
25°
9
34°
29°
10
37°
26°
11
33°
25°
12
32°
21°
13
32°
19°
14
30°
19°
15
29°
22°
16
30°
23°
17
32°
19°
18
30°
17°
19
30°
20°
20
31°
20°
21
29°
21°
22
30°
29°
23
35°
30°
24
37°
25°
25
37°
18°
26
33°
15°
27
28°
25°
28
37°
19°
29
37°
15°
30
28°
13°
31
26°
13°
1
27°
17°
2
29°
20°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Chicago
Chicago's December 2026 forecast shows daily high temperatures ranging from 26° to 47°, with overnight lows between 13° and 38°. The average high for December is 34° with an average low of 24°. 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 Chicago. See also: January | February | March.
