S
M
T
W
T
F
S
30
98°
74°
31
95°
69°
1
96°
72°
2
98°
73°
3
101°
71°
4
101°
73°
5
98°
71°
6
96°
69°
7
97°
74°
8
97°
74°
9
99°
74°
10
98°
73°
11
100°
73°
12
104°
74°
13
100°
72°
14
89°
65°
15
86°
64°
16
89°
66°
17
90°
66°
18
90°
64°
19
86°
63°
20
80°
54°
21
87°
64°
22
83°
63°
23
81°
63°
24
77°
62°
25
79°
62°
26
81°
61°
27
80°
62°
28
78°
61°
29
76°
52°
30
82°
49°
1
72°
49°
2
73°
48°
3
72°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Idalou
Idalou's September 2026 forecast shows daily high temperatures ranging from 72° to 104°, with overnight lows between 48° and 74°. The average high for September is 86° with an average low of 63°. 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 Idalou. See also: October | November | December.
