S
M
T
W
T
F
S
30
82°
63°
31
79°
69°
1
84°
68°
2
72°
65°
3
88°
67°
4
85°
73°
5
80°
68°
6
78°
64°
7
80°
57°
8
81°
58°
9
88°
63°
10
87°
70°
11
81°
59°
12
80°
69°
13
83°
66°
14
78°
57°
15
74°
63°
16
78°
62°
17
80°
58°
18
78°
57°
19
72°
51°
20
70°
51°
21
68°
52°
22
70°
52°
23
71°
54°
24
74°
52°
25
66°
47°
26
67°
47°
27
70°
55°
28
75°
52°
29
68°
47°
30
69°
54°
1
70°
52°
2
66°
48°
3
69°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Closter
Closter's September 2026 forecast shows daily high temperatures ranging from 66° to 83°, with overnight lows between 47° and 69°. The average high for September is 73° with an average low of 55°. 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 Closter. See also: October | November | December.