S
M
T
W
T
F
S
30
68°
56°
31
71°
56°
1
68°
58°
2
68°
51°
3
67°
53°
4
71°
51°
5
65°
50°
6
66°
46°
7
64°
55°
8
68°
56°
9
69°
47°
10
64°
45°
11
61°
49°
12
61°
44°
13
60°
43°
14
59°
42°
15
57°
43°
16
57°
42°
17
58°
41°
18
56°
43°
19
57°
44°
20
59°
47°
21
64°
48°
22
65°
53°
23
64°
49°
24
66°
51°
25
63°
45°
26
61°
41°
27
57°
40°
28
53°
48°
29
55°
46°
30
58°
47°
1
57°
41°
2
59°
38°
3
53°
45°
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 53° to 71°, with overnight lows between 38° and 58°. The average high for September is 62° with an average low of 47°. 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.
