S
M
T
W
T
F
S
30
84°
65°
31
90°
67°
1
88°
68°
2
86°
67°
3
79°
66°
4
81°
66°
5
81°
64°
6
78°
62°
7
76°
60°
8
74°
61°
9
78°
58°
10
74°
54°
11
71°
53°
12
72°
53°
13
71°
56°
14
77°
58°
15
77°
58°
16
77°
57°
17
75°
57°
18
75°
58°
19
76°
57°
20
76°
56°
21
75°
58°
22
76°
58°
23
76°
57°
24
75°
57°
25
75°
56°
26
74°
56°
27
75°
55°
28
75°
55°
29
73°
54°
30
72°
54°
1
72°
53°
2
73°
54°
3
72°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Oshkosh
Oshkosh's September 2026 forecast shows daily high temperatures ranging from 71° to 88°, with overnight lows between 52° and 68°. The average high for September is 76° with an average low of 58°. 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 Oshkosh. See also: October | November | December.
