S
M
T
W
T
F
S
30
82°
63°
31
80°
68°
1
89°
67°
2
73°
67°
3
89°
71°
4
88°
69°
5
83°
63°
6
80°
55°
7
82°
55°
8
85°
60°
9
87°
70°
10
89°
67°
11
83°
55°
12
82°
65°
13
85°
68°
14
77°
49°
15
75°
54°
16
83°
59°
17
84°
70°
18
86°
64°
19
72°
63°
20
70°
60°
21
75°
57°
22
67°
56°
23
69°
52°
24
66°
55°
25
70°
57°
26
62°
55°
27
65°
58°
28
66°
57°
29
73°
53°
30
79°
62°
1
78°
59°
2
87°
58°
3
74°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Bound Brook
Bound Brook's September 2026 forecast shows daily high temperatures ranging from 74° to 87°, with overnight lows between 52° and 59°. The average high for September is 80° with an average low of 56°. 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 Bound Brook. See also: October | November | December.