S
M
T
W
T
F
S
26
100°
68°
27
95°
70°
28
93°
64°
29
99°
63°
30
84°
57°
31
86°
55°
1
97°
59°
2
97°
66°
3
79°
48°
4
75°
45°
5
88°
50°
6
95°
57°
7
84°
52°
8
95°
61°
9
90°
55°
10
91°
55°
11
90°
59°
12
81°
59°
13
76°
59°
14
77°
58°
15
72°
56°
16
75°
59°
17
81°
64°
18
81°
63°
19
80°
60°
20
82°
58°
21
75°
59°
22
77°
58°
23
78°
59°
24
79°
59°
25
82°
54°
26
86°
61°
27
82°
60°
28
86°
61°
29
85°
60°
30
86°
61°
31
85°
60°
1
83°
60°
2
84°
59°
3
84°
59°
4
85°
58°
5
84°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Spearfish
Spearfish's August 2026 forecast shows daily high temperatures ranging from 72° to 86°, with overnight lows between 54° and 64°. The average high for August is 81° with an average low of 59°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Spearfish. See also: September | October | November.
