S
M
T
W
T
F
S
30
93°
72°
31
91°
72°
1
94°
70°
2
93°
71°
3
89°
69°
4
89°
66°
5
88°
64°
6
88°
65°
7
91°
71°
8
93°
72°
9
93°
72°
10
94°
70°
11
92°
70°
12
91°
69°
13
91°
69°
14
90°
68°
15
92°
69°
16
91°
69°
17
Hist. Avg.
87°
65°
18
Hist. Avg.
87°
64°
19
Hist. Avg.
86°
64°
20
Hist. Avg.
86°
64°
21
Hist. Avg.
86°
63°
22
Hist. Avg.
86°
63°
23
Hist. Avg.
85°
62°
24
Hist. Avg.
85°
62°
25
Hist. Avg.
85°
62°
26
Hist. Avg.
84°
61°
27
Hist. Avg.
84°
61°
28
Hist. Avg.
84°
61°
29
Hist. Avg.
84°
60°
30
Hist. Avg.
84°
60°
1
Hist. Avg.
83°
59°
2
Hist. Avg.
83°
59°
3
Hist. Avg.
83°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Princeton
Princeton's September 2026 forecast shows daily high temperatures ranging from 88° to 94°, with overnight lows between 64° and 72°. The average high for September is 91° with an average low of 69°. 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.
