S
M
T
W
T
F
S
26
54°
40°
27
66°
40°
28
64°
41°
29
62°
45°
30
58°
46°
1
64°
42°
2
59°
46°
3
60°
47°
4
70°
53°
5
74°
59°
6
64°
50°
7
57°
45°
8
64°
45°
9
61°
47°
10
66°
45°
11
67°
48°
12
68°
49°
13
66°
50°
14
67°
51°
15
68°
51°
16
70°
50°
17
76°
54°
18
76°
55°
19
75°
54°
20
75°
55°
21
74°
53°
22
74°
48°
23
70°
47°
24
67°
48°
25
69°
48°
26
69°
51°
27
70°
48°
28
69°
49°
29
70°
50°
30
70°
49°
31
71°
57°
1
76°
56°
2
72°
51°
3
72°
55°
4
77°
58°
5
74°
55°
6
73°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Old Greenwich
Old Greenwich's May 2026 forecast shows daily high temperatures ranging from 57° to 77°, with overnight lows between 45° and 59°. The average high for May is 70° with an average low of 51°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Old Greenwich. See also: June | July | August.
