S
M
T
W
T
F
S
26
96°
72°
27
97°
75°
28
93°
73°
29
92°
72°
30
81°
73°
31
74°
62°
1
86°
61°
2
88°
58°
3
90°
67°
4
72°
51°
5
80°
58°
6
86°
63°
7
90°
63°
8
92°
69°
9
87°
66°
10
92°
68°
11
86°
66°
12
90°
65°
13
87°
63°
14
83°
63°
15
83°
62°
16
85°
64°
17
83°
61°
18
87°
67°
19
85°
66°
20
85°
67°
21
86°
67°
22
87°
66°
23
84°
66°
24
84°
65°
25
83°
64°
26
77°
64°
27
77°
63°
28
84°
63°
29
85°
65°
30
86°
66°
31
86°
65°
1
85°
64°
2
86°
66°
3
86°
66°
4
85°
65°
5
85°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Sioux Falls
Sioux Falls's August 2026 forecast shows daily high temperatures ranging from 72° to 92°, with overnight lows between 51° and 69°. The average high for August is 85° with an average low of 64°. 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 Sioux Falls. See also: September | October | November.
