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