S
M
T
W
T
F
S
30
69°
61°
31
67°
60°
1
69°
57°
2
70°
56°
3
69°
59°
4
68°
59°
5
70°
60°
6
74°
58°
7
68°
56°
8
67°
55°
9
68°
54°
10
67°
54°
11
64°
50°
12
62°
49°
13
63°
50°
14
64°
49°
15
69°
55°
16
68°
55°
17
68°
54°
18
66°
56°
19
65°
55°
20
68°
54°
21
67°
55°
22
67°
54°
23
66°
54°
24
66°
55°
25
68°
55°
26
68°
53°
27
67°
54°
28
67°
52°
29
64°
51°
30
63°
52°
1
65°
53°
2
65°
51°
3
63°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grand Marais
Grand Marais's September 2026 forecast shows daily high temperatures ranging from 62° to 74°, with overnight lows between 49° and 60°. The average high for September is 67° with an average low of 54°. 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 Grand Marais. See also: October | November | December.
