S
M
T
W
T
F
S
29
32°
8°
30
29°
7°
1
30°
8°
2
30°
12°
3
35°
19°
4
30°
13°
5
29°
14°
6
29°
5°
7
28°
4°
8
33°
6°
9
39°
6°
10
39°
7°
11
38°
5°
12
39°
9°
13
38°
9°
14
33°
17°
15
27°
16°
16
33°
3°
17
28°
14°
18
27°
17°
19
29°
18°
20
31°
15°
21
32°
3°
22
29°
9°
23
28°
3°
24
30°
10°
25
27°
19°
26
32°
12°
27
36°
0°
28
31°
12°
29
23°
1°
30
27°
3°
31
23°
7°
1
30°
16°
2
33°
8°
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 23° to 39°, with overnight lows between -0° and 19°. The average high for December is 31° with an average low of 10°. 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.
