S
M
T
W
T
F
S
29
50°
24°
30
48°
21°
1
36°
23°
2
36°
26°
3
43°
27°
4
44°
33°
5
45°
33°
6
46°
32°
7
47°
31°
8
46°
28°
9
41°
27°
10
40°
21°
11
37°
17°
12
32°
20°
13
33°
17°
14
31°
18°
15
30°
17°
16
32°
14°
17
30°
16°
18
28°
22°
19
34°
24°
20
38°
27°
21
40°
27°
22
39°
20°
23
39°
15°
24
33°
12°
25
27°
17°
26
28°
21°
27
31°
22°
28
39°
15°
29
34°
16°
30
29°
16°
31
30°
22°
1
33°
22°
2
37°
19°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in New Lenox
New Lenox's December 2026 forecast shows daily high temperatures ranging from 27° to 50°, with overnight lows between 12° and 33°. The average high for December is 37° with an average low of 22°. 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 New Lenox. See also: January | February | March.
