S
M
T
W
T
F
S
30
77°
64°
31
N/A
1
91°
69°
2
94°
68°
3
83°
65°
4
82°
62°
5
77°
61°
6
77°
58°
7
74°
57°
8
75°
56°
9
77°
59°
10
76°
56°
11
72°
52°
12
73°
52°
13
71°
53°
14
73°
51°
15
76°
56°
16
77°
57°
17
77°
56°
18
73°
55°
19
77°
57°
20
78°
57°
21
78°
56°
22
77°
56°
23
77°
55°
24
76°
55°
25
75°
54°
26
76°
53°
27
75°
54°
28
75°
53°
29
74°
52°
30
72°
52°
1
72°
51°
2
73°
52°
3
73°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in South Lyon
South Lyon's September 2026 forecast shows daily high temperatures ranging from 71° to 94°, with overnight lows between 51° and 69°. The average high for September is 77° with an average low of 56°. 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 South Lyon. See also: October | November | December.
