S
M
T
W
T
F
S
30
79°
62°
31
77°
68°
1
78°
66°
2
75°
65°
3
85°
70°
4
84°
70°
5
80°
66°
6
73°
60°
7
79°
56°
8
80°
61°
9
79°
62°
10
86°
70°
11
78°
62°
12
76°
66°
13
79°
68°
14
76°
54°
15
73°
59°
16
76°
65°
17
80°
65°
18
77°
65°
19
75°
59°
20
72°
57°
21
72°
57°
22
72°
55°
23
70°
58°
24
71°
55°
25
72°
55°
26
66°
52°
27
67°
59°
28
74°
58°
29
74°
56°
30
67°
53°
1
66°
53°
2
68°
57°
3
72°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Islip Terrace
Islip Terrace's September 2026 forecast shows daily high temperatures ranging from 66° to 80°, with overnight lows between 52° and 68°. 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 Islip Terrace. See also: October | November | December.
