S
M
T
W
T
F
S
30
79°
63°
31
82°
67°
1
84°
67°
2
84°
66°
3
85°
60°
4
83°
58°
5
77°
59°
6
77°
65°
7
78°
65°
8
82°
64°
9
82°
65°
10
78°
64°
11
82°
63°
12
82°
64°
13
81°
64°
14
80°
65°
15
82°
64°
16
82°
60°
17
80°
63°
18
79°
58°
19
79°
56°
20
74°
55°
21
72°
53°
22
71°
60°
23
72°
57°
24
76°
54°
25
71°
53°
26
70°
53°
27
72°
55°
28
76°
59°
29
75°
57°
30
76°
55°
1
70°
58°
2
70°
51°
3
68°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Old Westbury
Old Westbury's September 2026 forecast shows daily high temperatures ranging from 68° to 85°, with overnight lows between 51° and 67°. The average high for September is 77° with an average low of 60°. 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 Old Westbury. See also: October | November | December.
