S
M
T
W
T
F
S
30
78°
60°
31
78°
66°
1
78°
63°
2
69°
61°
3
83°
67°
4
82°
68°
5
78°
62°
6
73°
59°
7
80°
62°
8
82°
66°
9
84°
71°
10
84°
65°
11
77°
60°
12
77°
61°
13
79°
63°
14
82°
63°
15
78°
62°
16
77°
56°
17
75°
59°
18
74°
58°
19
73°
57°
20
72°
55°
21
74°
59°
22
68°
58°
23
68°
58°
24
69°
57°
25
70°
54°
26
73°
54°
27
69°
51°
28
68°
54°
29
73°
57°
30
74°
57°
1
74°
56°
2
72°
57°
3
71°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Greenwich
Greenwich's September 2026 forecast shows daily high temperatures ranging from 68° to 84°, with overnight lows between 51° and 71°. The average high for September is 75° with an average low of 59°. 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 Greenwich. See also: October | November | December.
