S
M
T
W
T
F
S
30
80°
54°
31
81°
55°
1
81°
55°
2
80°
56°
3
80°
56°
4
80°
55°
5
80°
56°
6
78°
54°
7
76°
55°
8
77°
55°
9
77°
53°
10
78°
54°
11
79°
53°
12
79°
53°
13
78°
54°
14
78°
54°
15
76°
53°
16
76°
52°
17
74°
52°
18
73°
48°
19
71°
40°
20
65°
45°
21
67°
49°
22
68°
42°
23
65°
41°
24
64°
43°
25
66°
49°
26
72°
49°
27
64°
45°
28
64°
41°
29
63°
40°
30
63°
41°
1
65°
48°
2
66°
48°
3
61°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Princetown
Princetown's September 2026 forecast shows daily high temperatures ranging from 61° to 81°, with overnight lows between 40° and 56°. The average high for September is 73° with an average low of 50°. 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 Princetown. See also: October | November | December.
