S
M
T
W
T
F
S
30
64°
62°
31
71°
62°
1
85°
63°
2
76°
62°
3
69°
62°
4
64°
60°
5
69°
60°
6
70°
62°
7
69°
65°
8
76°
61°
9
74°
53°
10
69°
58°
11
73°
59°
12
70°
59°
13
72°
55°
14
71°
58°
15
73°
56°
16
67°
50°
17
70°
56°
18
71°
55°
19
70°
56°
20
71°
55°
21
66°
55°
22
67°
54°
23
67°
55°
24
69°
54°
25
68°
51°
26
60°
47°
27
57°
44°
28
55°
44°
29
63°
45°
30
55°
41°
1
54°
49°
2
54°
48°
3
56°
47°
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 54° to 76°, with overnight lows between 41° and 65°. The average high for September is 66° 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 Duluth. See also: October | November | December.
