S
M
T
W
T
F
S
29
49°
40°
30
55°
40°
1
54°
41°
2
55°
40°
3
57°
39°
4
47°
36°
5
52°
38°
6
52°
38°
7
51°
35°
8
44°
32°
9
43°
28°
10
41°
29°
11
41°
33°
12
42°
31°
13
44°
30°
14
38°
23°
15
41°
26°
16
41°
32°
17
44°
33°
18
42°
35°
19
49°
28°
20
45°
20°
21
39°
20°
22
36°
22°
23
36°
27°
24
37°
27°
25
50°
28°
26
41°
22°
27
39°
19°
28
36°
19°
29
36°
20°
30
40°
34°
31
50°
26°
1
53°
20°
2
39°
17°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in McLean
McLean's December 2026 forecast shows daily high temperatures ranging from 36° to 57°, with overnight lows between 17° and 41°. The average high for December is 45° 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 McLean. See also: January | February | March.
