S
M
T
W
T
F
S
30
81°
55°
31
80°
56°
1
81°
54°
2
78°
53°
3
79°
53°
4
79°
55°
5
80°
58°
6
79°
58°
7
85°
53°
8
82°
57°
9
82°
62°
10
83°
62°
11
84°
60°
12
85°
50°
13
79°
59°
14
76°
57°
15
83°
59°
16
76°
57°
17
81°
49°
18
75°
51°
19
76°
58°
20
78°
47°
21
81°
46°
22
72°
45°
23
Hist. Avg.
77°
52°
24
Hist. Avg.
76°
51°
25
Hist. Avg.
76°
51°
26
Hist. Avg.
75°
50°
27
Hist. Avg.
75°
50°
28
Hist. Avg.
75°
49°
29
Hist. Avg.
74°
49°
30
Hist. Avg.
74°
48°
1
Hist. Avg.
73°
48°
2
Hist. Avg.
73°
47°
3
Hist. Avg.
73°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Duluth
Duluth's September 2026 forecast shows daily high temperatures ranging from 72° to 85°, with overnight lows between 45° and 62°. The average high for September is 80° 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.
