S
M
T
W
T
F
S
26
50°
27°
27
34°
30°
28
50°
32°
29
54°
34°
30
54°
27°
1
57°
34°
2
73°
37°
3
68°
45°
4
55°
39°
5
45°
28°
6
54°
27°
7
61°
30°
8
68°
45°
9
59°
39°
10
70°
41°
11
84°
48°
12
70°
45°
13
88°
41°
14
75°
48°
15
73°
43°
16
74°
43°
17
57°
35°
18
40°
33°
19
54°
40°
20
64°
43°
21
64°
46°
22
72°
49°
23
69°
48°
24
73°
49°
25
75°
48°
26
78°
54°
27
77°
56°
28
78°
56°
29
69°
47°
30
73°
52°
31
74°
51°
1
69°
52°
2
68°
52°
3
66°
51°
4
74°
54°
5
74°
53°
6
68°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Spearfish
Spearfish's May 2026 forecast shows daily high temperatures ranging from 40° to 78°, with overnight lows between 33° and 56°. The average high for May is 69° with an average low of 48°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Spearfish. See also: June | July | August.
