S
M
T
W
T
F
S
29
41°
27°
30
34°
23°
1
43°
26°
2
38°
27°
3
33°
18°
4
34°
26°
5
41°
27°
6
40°
26°
7
39°
25°
8
38°
27°
9
32°
22°
10
31°
18°
11
31°
22°
12
36°
25°
13
35°
25°
14
41°
24°
15
39°
26°
16
44°
26°
17
43°
25°
18
40°
23°
19
34°
20°
20
36°
24°
21
39°
25°
22
38°
18°
23
28°
18°
24
42°
26°
25
32°
13°
26
35°
20°
27
35°
11°
28
32°
14°
29
31°
9°
30
30°
7°
31
28°
8°
1
28°
13°
2
28°
14°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Spearfish
Spearfish's December 2026 forecast shows daily high temperatures ranging from 28° to 44°, with overnight lows between 7° and 27°. The average high for December is 36° with an average low of 21°. 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 Spearfish. See also: January | February | March.
