S
M
T
W
T
F
S
26
55°
43°
27
58°
44°
28
52°
43°
29
50°
45°
30
56°
46°
1
65°
47°
2
55°
48°
3
55°
44°
4
73°
46°
5
79°
50°
6
70°
57°
7
65°
50°
8
62°
47°
9
55°
42°
10
75°
51°
11
62°
49°
12
64°
48°
13
64°
46°
14
62°
49°
15
55°
47°
16
77°
59°
17
83°
53°
18
74°
59°
19
87°
68°
20
82°
60°
21
67°
50°
22
64°
53°
23
64°
53°
24
66°
54°
25
67°
55°
26
72°
60°
27
73°
54°
28
64°
52°
29
64°
53°
30
65°
58°
31
67°
58°
1
67°
57°
2
68°
56°
3
67°
54°
4
66°
53°
5
67°
58°
6
69°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in South Boston
South Boston's May 2026 forecast shows daily high temperatures ranging from 55° to 87°, with overnight lows between 47° and 68°. The average high for May is 69° with an average low of 55°. 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 South Boston. See also: June | July | August.
