S
M
T
W
T
F
S
29
35°
28°
30
37°
30°
1
35°
35°
2
38°
35°
3
39°
36°
4
42°
36°
5
41°
35°
6
44°
36°
7
42°
35°
8
40°
35°
9
38°
34°
10
36°
33°
11
43°
28°
12
39°
28°
13
36°
19°
14
34°
18°
15
30°
22°
16
32°
23°
17
30°
28°
18
35°
30°
19
35°
27°
20
37°
30°
21
36°
30°
22
36°
31°
23
41°
30°
24
43°
24°
25
40°
19°
26
34°
19°
27
29°
25°
28
33°
28°
29
39°
28°
30
39°
32°
31
42°
32°
1
42°
25°
2
44°
19°
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 29° to 44°, with overnight lows between 18° and 36°. The average high for December is 38° with an average low of 29°. 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.
