S
M
T
W
T
F
S
30
75°
63°
31
79°
68°
1
81°
69°
2
80°
68°
3
76°
65°
4
75°
62°
5
74°
61°
6
74°
59°
7
75°
66°
8
80°
61°
9
73°
58°
10
73°
57°
11
76°
55°
12
71°
57°
13
71°
57°
14
70°
56°
15
71°
57°
16
72°
56°
17
71°
55°
18
75°
57°
19
70°
54°
20
70°
53°
21
69°
53°
22
69°
54°
23
71°
57°
24
75°
53°
25
75°
58°
26
74°
59°
27
69°
55°
28
67°
55°
29
73°
53°
30
72°
50°
1
66°
53°
2
71°
58°
3
72°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Fire Island
Fire Island's September 2026 forecast shows daily high temperatures ranging from 66° to 81°, with overnight lows between 48° and 69°. The average high for September is 73° with an average low of 58°. 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 Fire Island. See also: October | November | December.
