S
M
T
W
T
F
S
26
97°
74°
27
94°
78°
28
88°
72°
29
86°
66°
30
86°
62°
31
83°
65°
1
75°
62°
2
82°
59°
3
83°
60°
4
84°
64°
5
81°
64°
6
82°
65°
7
85°
65°
8
84°
64°
9
85°
63°
10
87°
63°
11
87°
64°
12
85°
61°
13
85°
64°
14
88°
63°
15
79°
63°
16
82°
67°
17
90°
69°
18
90°
68°
19
89°
68°
20
87°
66°
21
87°
67°
22
89°
67°
23
89°
66°
24
87°
66°
25
87°
65°
26
86°
63°
27
86°
64°
28
87°
63°
29
85°
64°
30
86°
65°
31
86°
64°
1
87°
65°
2
87°
65°
3
86°
64°
4
86°
63°
5
85°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Ottumwa
Ottumwa's August 2026 forecast shows daily high temperatures ranging from 75° to 90°, with overnight lows between 59° 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 Ottumwa. See also: September | October | November.
