S
M
T
W
T
F
S
30
84°
71°
31
84°
70°
1
83°
66°
2
76°
63°
3
75°
63°
4
76°
64°
5
76°
62°
6
80°
67°
7
82°
69°
8
82°
69°
9
78°
68°
10
81°
69°
11
82°
68°
12
81°
69°
13
82°
70°
14
81°
59°
15
74°
59°
16
71°
60°
17
72°
59°
18
72°
57°
19
71°
58°
20
71°
58°
21
77°
60°
22
77°
64°
23
76°
56°
24
77°
56°
25
72°
55°
26
69°
57°
27
73°
62°
28
74°
62°
29
75°
54°
30
71°
55°
1
67°
59°
2
68°
60°
3
72°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Roosevelt Island
Roosevelt Island's September 2026 forecast shows daily high temperatures ranging from 67° to 84°, with overnight lows between 54° and 71°. The average high for September is 76° with an average low of 62°. 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 Roosevelt Island. See also: October | November | December.
