S
M
T
W
T
F
S
30
84°
56°
31
78°
67°
1
88°
70°
2
72°
67°
3
88°
68°
4
86°
73°
5
81°
65°
6
79°
61°
7
79°
59°
8
82°
56°
9
87°
61°
10
87°
71°
11
80°
60°
12
81°
56°
13
82°
66°
14
75°
56°
15
74°
51°
16
82°
56°
17
84°
67°
18
83°
65°
19
73°
61°
20
73°
63°
21
73°
61°
22
65°
56°
23
69°
53°
24
65°
50°
25
70°
55°
26
64°
55°
27
65°
57°
28
67°
59°
29
73°
57°
30
76°
56°
1
79°
61°
2
87°
62°
3
72°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Princeton
Princeton's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Princeton. See also: October | November | December.
