S
M
T
W
T
F
S
30
91°
72°
31
92°
71°
1
92°
71°
2
91°
70°
3
87°
70°
4
87°
69°
5
88°
70°
6
88°
68°
7
90°
65°
8
91°
67°
9
91°
68°
10
89°
67°
11
90°
68°
12
88°
67°
13
89°
68°
14
84°
66°
15
87°
67°
16
89°
65°
17
84°
64°
18
83°
63°
19
83°
62°
20
84°
63°
21
87°
65°
22
88°
65°
23
87°
64°
24
84°
64°
25
86°
65°
26
83°
64°
27
82°
64°
28
83°
63°
29
85°
63°
30
86°
61°
1
82°
62°
2
83°
61°
3
80°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Lyons
Lyons's September 2026 forecast shows daily high temperatures ranging from 80° to 92°, with overnight lows between 61° and 72°. The average high for September is 87° with an average low of 66°. 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 Lyons. See also: October | November | December.