S
M
T
W
T
F
S
30
84°
62°
31
83°
61°
1
84°
59°
2
82°
58°
3
82°
58°
4
81°
59°
5
82°
60°
6
82°
60°
7
86°
59°
8
85°
61°
9
83°
65°
10
82°
65°
11
87°
64°
12
88°
57°
13
85°
65°
14
80°
64°
15
85°
64°
16
85°
63°
17
86°
56°
18
84°
55°
19
77°
63°
20
83°
53°
21
84°
52°
22
75°
51°
23
76°
59°
24
80°
61°
25
Hist. Avg.
79°
55°
26
Hist. Avg.
79°
55°
27
Hist. Avg.
78°
55°
28
Hist. Avg.
78°
54°
29
Hist. Avg.
78°
54°
30
Hist. Avg.
77°
53°
1
Hist. Avg.
77°
53°
2
Hist. Avg.
76°
52°
3
Hist. Avg.
76°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Oswego
Oswego's September 2026 forecast shows daily high temperatures ranging from 75° to 88°, with overnight lows between 51° and 65°. The average high for September is 83° with an average low of 60°. 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 Oswego. See also: October | November | December.
