S
M
T
W
T
F
S
30
77°
64°
31
87°
71°
1
90°
73°
2
93°
75°
3
88°
69°
4
82°
65°
5
78°
56°
6
78°
59°
7
79°
58°
8
75°
57°
9
76°
58°
10
77°
58°
11
74°
55°
12
74°
54°
13
72°
56°
14
74°
54°
15
78°
60°
16
78°
59°
17
77°
58°
18
73°
57°
19
77°
58°
20
78°
59°
21
78°
59°
22
77°
58°
23
78°
58°
24
78°
57°
25
77°
56°
26
77°
55°
27
76°
56°
28
76°
55°
29
75°
54°
30
74°
54°
1
73°
53°
2
73°
54°
3
74°
54°
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 72° to 93°, with overnight lows between 53° and 75°. The average high for September is 77° with an average low of 58°. 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.
