S
M
T
W
T
F
S
30
80°
55°
31
78°
54°
1
79°
55°
2
79°
56°
3
77°
59°
4
78°
55°
5
80°
56°
6
79°
55°
7
78°
53°
8
77°
54°
9
77°
53°
10
78°
57°
11
77°
52°
12
76°
52°
13
77°
51°
14
78°
56°
15
78°
57°
16
80°
55°
17
75°
50°
18
74°
49°
19
74°
50°
20
77°
55°
21
75°
50°
22
73°
52°
23
78°
55°
24
77°
56°
25
78°
54°
26
77°
46°
27
77°
47°
28
69°
46°
29
68°
45°
30
68°
45°
1
Hist. Avg.
72°
50°
2
Hist. Avg.
72°
50°
3
Hist. Avg.
72°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Monmouth Junction
Monmouth Junction's September 2026 forecast shows daily high temperatures ranging from 68° to 80°, with overnight lows between 45° and 59°. The average high for September is 76° with an average low of 53°. 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 Monmouth Junction. See also: October | November | December.
