S
M
T
W
T
F
S
30
73°
50°
31
73°
53°
1
72°
54°
2
72°
50°
3
73°
50°
4
75°
52°
5
71°
50°
6
70°
49°
7
71°
49°
8
78°
50°
9
79°
53°
10
80°
57°
11
79°
56°
12
80°
57°
13
79°
56°
14
76°
47°
15
73°
49°
16
72°
56°
17
78°
57°
18
79°
50°
19
78°
53°
20
76°
55°
21
72°
55°
22
76°
54°
23
77°
52°
24
74°
54°
25
74°
57°
26
75°
57°
27
75°
54°
28
65°
51°
29
64°
52°
30
65°
52°
1
64°
50°
2
62°
45°
3
61°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Deer Island
Deer Island's September 2026 forecast shows daily high temperatures ranging from 61° to 80°, with overnight lows between 45° and 57°. The average high for September is 73° with an average low of 52°. 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 Deer Island. See also: October | November | December.
