S
M
T
W
T
F
S
30
77°
60°
31
77°
59°
1
70°
58°
2
68°
58°
3
71°
59°
4
75°
59°
5
75°
58°
6
76°
59°
7
76°
59°
8
75°
58°
9
73°
57°
10
72°
58°
11
74°
57°
12
70°
56°
13
66°
56°
14
62°
45°
15
63°
50°
16
64°
50°
17
67°
51°
18
65°
48°
19
66°
53°
20
70°
54°
21
71°
53°
22
70°
46°
23
67°
47°
24
65°
51°
25
68°
52°
26
69°
45°
27
68°
41°
28
64°
41°
29
58°
44°
30
60°
47°
1
64°
44°
2
61°
49°
3
63°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mackinac Island
Mackinac Island's September 2026 forecast shows daily high temperatures ranging from 58° to 77°, with overnight lows between 41° and 60°. The average high for September is 69° with an average low of 52°. 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 Mackinac Island. See also: October | November | December.
