S
M
T
W
T
F
S
29
28°
17°
30
30°
19°
1
32°
23°
2
32°
23°
3
35°
22°
4
35°
22°
5
34°
21°
6
35°
21°
7
36°
20°
8
34°
20°
9
35°
19°
10
32°
19°
11
31°
14°
12
28°
12°
13
26°
10°
14
28°
15°
15
29°
12°
16
28°
15°
17
33°
15°
18
32°
14°
19
32°
14°
20
33°
13°
21
33°
14°
22
31°
13°
23
33°
7°
24
32°
1°
25
24°
9°
26
21°
8°
27
22°
10°
28
24°
8°
29
31°
8°
30
28°
10°
31
28°
11°
1
30°
0°
2
30°
-5°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Riverton
Riverton's December 2026 forecast shows daily high temperatures ranging from 21° to 36°, with overnight lows between -5° and 23°. The average high for December is 30° with an average low of 14°. 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 Riverton. See also: January | February | March.