S
M
T
W
T
F
S
31
84°
69°
1
85°
71°
2
89°
68°
3
88°
65°
4
95°
64°
5
90°
64°
6
78°
60°
7
82°
64°
8
82°
60°
9
85°
61°
10
89°
62°
11
94°
62°
12
95°
67°
13
91°
68°
14
91°
68°
15
93°
67°
16
92°
65°
17
96°
67°
18
91°
67°
19
90°
68°
20
92°
69°
21
84°
71°
22
92°
70°
23
98°
74°
24
83°
69°
25
85°
64°
26
88°
62°
27
89°
61°
28
86°
61°
29
83°
59°
30
86°
64°
1
89°
61°
2
90°
63°
3
90°
64°
4
88°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Illinois Bend
Illinois Bend's September 2025 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Illinois Bend. See also: October | November | December.
