S
M
T
W
T
F
S
26
96°
71°
27
97°
77°
28
91°
71°
29
92°
69°
30
80°
71°
31
74°
62°
1
85°
60°
2
89°
62°
3
93°
66°
4
75°
56°
5
77°
52°
6
84°
59°
7
89°
66°
8
91°
69°
9
90°
71°
10
96°
70°
11
98°
66°
12
87°
65°
13
87°
64°
14
86°
65°
15
84°
61°
16
88°
66°
17
88°
69°
18
89°
67°
19
87°
66°
20
87°
66°
21
88°
67°
22
89°
66°
23
86°
66°
24
84°
65°
25
84°
64°
26
79°
63°
27
81°
63°
28
86°
62°
29
86°
64°
30
87°
65°
31
87°
64°
1
88°
63°
2
88°
65°
3
87°
65°
4
88°
64°
5
87°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in South Sioux City
South Sioux City's August 2026 forecast shows daily high temperatures ranging from 75° to 98°, with overnight lows between 52° and 71°. The average high for August is 87° 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 South Sioux City. See also: September | October | November.
