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