S
M
T
W
T
F
S
30
73°
66°
31
77°
63°
1
81°
62°
2
79°
59°
3
76°
59°
4
68°
62°
5
76°
55°
6
75°
51°
7
75°
52°
8
71°
65°
9
85°
56°
10
73°
51°
11
75°
47°
12
78°
50°
13
67°
44°
14
66°
37°
15
76°
49°
16
68°
44°
17
71°
49°
18
65°
57°
19
64°
53°
20
66°
52°
21
61°
51°
22
61°
52°
23
62°
50°
24
64°
49°
25
66°
53°
26
65°
52°
27
64°
50°
28
65°
52°
29
66°
53°
30
64°
51°
1
63°
45°
2
58°
51°
3
60°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Washington Island
Washington Island's September 2026 forecast shows daily high temperatures ranging from 58° to 66°, with overnight lows between 45° and 57°. The average high for September is 63° with an average low of 51°. 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 Washington Island. See also: October | November | December.
