S
M
T
W
T
F
S
30
80°
55°
31
N/A
1
73°
62°
2
72°
64°
3
77°
64°
4
84°
61°
5
74°
60°
6
73°
59°
7
76°
63°
8
74°
59°
9
75°
64°
10
74°
63°
11
74°
62°
12
75°
60°
13
75°
59°
14
73°
60°
15
70°
59°
16
70°
62°
17
74°
60°
18
69°
56°
19
69°
57°
20
70°
60°
21
72°
61°
22
76°
62°
23
76°
61°
24
75°
59°
25
74°
58°
26
74°
59°
27
75°
60°
28
74°
59°
29
73°
57°
30
66°
53°
1
64°
53°
2
65°
57°
3
71°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Stonington
Stonington's September 2026 forecast shows daily high temperatures ranging from 64° to 84°, with overnight lows between 53° and 64°. The average high for September is 73° with an average low of 60°. 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 Stonington. See also: October | November | December.
