S
M
T
W
T
F
S
30
76°
65°
31
85°
68°
1
86°
68°
2
80°
64°
3
80°
61°
4
73°
63°
5
80°
57°
6
79°
53°
7
N/A
8
74°
66°
9
77°
57°
10
71°
50°
11
78°
58°
12
76°
57°
13
69°
57°
14
68°
59°
15
67°
55°
16
66°
53°
17
64°
52°
18
62°
51°
19
63°
50°
20
63°
51°
21
62°
50°
22
66°
55°
23
67°
54°
24
68°
56°
25
71°
55°
26
67°
54°
27
67°
55°
28
70°
56°
29
70°
56°
30
71°
57°
1
70°
53°
2
68°
51°
3
57°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Petoskey
Petoskey's September 2026 forecast shows daily high temperatures ranging from 57° to 78°, with overnight lows between 50° and 66°. The average high for September is 68° with an average low of 55°. 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 Petoskey. See also: October | November | December.