S
M
T
W
T
F
S
30
72°
54°
31
73°
52°
1
74°
53°
2
73°
52°
3
74°
53°
4
75°
51°
5
75°
52°
6
74°
53°
7
72°
50°
8
73°
49°
9
71°
52°
10
71°
49°
11
72°
48°
12
71°
48°
13
73°
54°
14
73°
49°
15
76°
51°
16
77°
55°
17
77°
56°
18
78°
54°
19
77°
45°
20
71°
46°
21
67°
52°
22
68°
52°
23
70°
53°
24
74°
54°
25
73°
44°
26
72°
42°
27
68°
44°
28
64°
43°
29
64°
43°
30
63°
43°
1
64°
50°
2
Hist. Avg.
69°
46°
3
Hist. Avg.
68°
45°
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 63° to 78°, with overnight lows between 42° and 56°. The average high for September is 72° with an average low of 50°. 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.
