S
M
T
W
T
F
S
30
82°
64°
31
85°
56°
1
86°
54°
2
78°
55°
3
77°
61°
4
80°
62°
5
84°
54°
6
84°
52°
7
76°
54°
8
77°
61°
9
79°
58°
10
80°
59°
11
76°
55°
12
74°
52°
13
74°
50°
14
73°
50°
15
73°
55°
16
74°
57°
17
77°
57°
18
81°
58°
19
81°
57°
20
76°
56°
21
80°
55°
22
76°
49°
23
78°
48°
24
73°
47°
25
69°
47°
26
70°
46°
27
Hist. Avg.
73°
49°
28
Hist. Avg.
73°
49°
29
Hist. Avg.
72°
48°
30
Hist. Avg.
72°
48°
1
Hist. Avg.
71°
48°
2
Hist. Avg.
71°
47°
3
Hist. Avg.
70°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Ottumwa
Ottumwa's September 2026 forecast shows daily high temperatures ranging from 69° to 86°, with overnight lows between 46° and 64°. The average high for September is 78° with an average low of 55°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Ottumwa. See also: October | November | December.
