S
M
T
W
T
F
S
30
80°
60°
31
84°
59°
1
84°
59°
2
83°
57°
3
82°
57°
4
78°
58°
5
81°
57°
6
83°
49°
7
79°
48°
8
72°
48°
9
73°
55°
10
72°
56°
11
79°
55°
12
77°
55°
13
81°
46°
14
77°
46°
15
70°
47°
16
69°
49°
17
69°
43°
18
70°
43°
19
73°
41°
20
69°
43°
21
68°
50°
22
70°
50°
23
77°
51°
24
77°
51°
25
76°
50°
26
76°
51°
27
77°
50°
28
75°
45°
29
71°
46°
30
70°
46°
1
71°
44°
2
74°
47°
3
Hist. Avg.
68°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Webster City
Webster City's September 2026 forecast shows daily high temperatures ranging from 68° to 84°, with overnight lows between 41° and 60°. The average high for September is 76° 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 September weather will actually feel in Webster City. See also: October | November | December.