S
M
T
W
T
F
S
26
83°
64°
27
83°
64°
28
87°
58°
29
93°
60°
30
83°
58°
31
80°
54°
1
83°
61°
2
87°
56°
3
68°
55°
4
65°
45°
5
69°
49°
6
75°
45°
7
70°
47°
8
69°
45°
9
70°
51°
10
70°
50°
11
71°
51°
12
70°
49°
13
73°
52°
14
74°
51°
15
75°
50°
16
75°
51°
17
71°
47°
18
72°
51°
19
77°
53°
20
77°
54°
21
76°
54°
22
77°
53°
23
76°
54°
24
77°
51°
25
71°
51°
26
65°
50°
27
71°
51°
28
74°
51°
29
75°
52°
30
74°
51°
31
69°
50°
1
72°
51°
2
73°
51°
3
73°
50°
4
71°
49°
5
72°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Rapid City
Rapid City's August 2026 forecast shows daily high temperatures ranging from 65° to 77°, with overnight lows between 45° and 54°. The average high for August is 72° with an average low of 50°. 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 Rapid City. See also: September | October | November.
