S
M
T
W
T
F
S
30
64°
62°
31
71°
62°
1
85°
63°
2
76°
62°
3
66°
62°
4
64°
62°
5
64°
61°
6
70°
61°
7
71°
62°
8
80°
60°
9
74°
51°
10
76°
56°
11
77°
58°
12
70°
50°
13
66°
50°
14
67°
51°
15
67°
52°
16
66°
53°
17
68°
53°
18
65°
52°
19
66°
49°
20
71°
55°
21
62°
54°
22
65°
55°
23
69°
55°
24
69°
54°
25
65°
53°
26
63°
53°
27
66°
55°
28
66°
54°
29
64°
52°
30
60°
52°
1
56°
47°
2
54°
44°
3
52°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Duluth
Duluth's September 2026 forecast shows daily high temperatures ranging from 52° to 80°, with overnight lows between 41° and 62°. The average high for September is 67° with an average low of 53°. 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 Duluth. See also: October | November | December.
