S
M
T
W
T
F
S
30
80°
52°
31
72°
52°
1
72°
59°
2
73°
56°
3
74°
52°
4
77°
59°
5
79°
57°
6
80°
50°
7
70°
49°
8
70°
48°
9
71°
50°
10
75°
53°
11
75°
49°
12
68°
48°
13
68°
47°
14
70°
55°
15
74°
54°
16
76°
46°
17
73°
45°
18
66°
44°
19
66°
46°
20
67°
50°
21
64°
51°
22
65°
45°
23
65°
48°
24
66°
44°
25
67°
52°
26
71°
52°
27
71°
43°
28
70°
43°
29
63°
49°
30
64°
50°
1
62°
51°
2
63°
48°
3
62°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Newtown
Newtown's September 2026 forecast shows daily high temperatures ranging from 62° to 80°, with overnight lows between 41° and 59°. The average high for September is 70° 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 Newtown. See also: October | November | December.
