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