S
M
T
W
T
F
S
30
72°
55°
31
66°
58°
1
67°
57°
2
65°
56°
3
69°
57°
4
72°
59°
5
72°
59°
6
74°
58°
7
74°
59°
8
73°
60°
9
74°
59°
10
74°
59°
11
73°
58°
12
73°
54°
13
67°
54°
14
63°
56°
15
72°
57°
16
72°
57°
17
71°
56°
18
71°
56°
19
70°
55°
20
71°
56°
21
71°
56°
22
70°
57°
23
71°
57°
24
70°
56°
25
70°
55°
26
68°
55°
27
68°
54°
28
64°
47°
29
61°
41°
30
55°
40°
1
62°
48°
2
66°
49°
3
65°
51°
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 55° to 74°, with overnight lows between 40° and 60°. The average high for September is 69° with an average low of 55°. 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.
