S
M
T
W
T
F
S
29
45°
29°
30
42°
25°
1
30°
20°
2
29°
17°
3
33°
27°
4
40°
27°
5
33°
26°
6
33°
22°
7
27°
17°
8
26°
20°
9
34°
22°
10
39°
25°
11
39°
25°
12
40°
24°
13
38°
25°
14
29°
23°
15
34°
21°
16
34°
19°
17
32°
16°
18
31°
14°
19
29°
8°
20
23°
7°
21
21°
19°
22
33°
19°
23
34°
15°
24
32°
6°
25
28°
15°
26
26°
21°
27
33°
20°
28
33°
18°
29
31°
12°
30
31°
12°
31
28°
2°
1
27°
0°
2
18°
9°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Alta
Alta's December 2026 forecast shows daily high temperatures ranging from 18° to 45°, with overnight lows between -0° and 29°. The average high for December is 32° with an average low of 18°. 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 Alta. See also: January | February | March.
