S
M
T
W
T
F
S
30
72°
47°
31
71°
49°
1
70°
48°
2
70°
48°
3
71°
49°
4
71°
46°
5
69°
48°
6
70°
52°
7
70°
54°
8
69°
53°
9
72°
51°
10
72°
51°
11
68°
49°
12
67°
52°
13
71°
51°
14
74°
54°
15
73°
52°
16
74°
54°
17
75°
53°
18
74°
53°
19
73°
50°
20
Hist. Avg.
64°
39°
21
Hist. Avg.
63°
39°
22
Hist. Avg.
63°
38°
23
Hist. Avg.
62°
38°
24
Hist. Avg.
62°
38°
25
Hist. Avg.
61°
38°
26
Hist. Avg.
61°
37°
27
Hist. Avg.
61°
37°
28
Hist. Avg.
60°
37°
29
Hist. Avg.
60°
36°
30
Hist. Avg.
59°
36°
1
Hist. Avg.
59°
36°
2
Hist. Avg.
58°
35°
3
Hist. Avg.
58°
35°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Ontonagon
Ontonagon's September 2026 forecast shows daily high temperatures ranging from 67° to 75°, with overnight lows between 46° and 54°. The average high for September is 71° with an average low of 51°. 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 Ontonagon. See also: October | November | December.
