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
63°
51°
15
55°
50°
16
80°
49°
17
90°
59°
18
71°
59°
19
93°
70°
20
92°
56°
21
64°
48°
22
64°
50°
23
60°
53°
24
56°
53°
25
60°
59°
26
68°
57°
27
69°
55°
28
69°
58°
29
69°
57°
30
73°
58°
31
78°
62°
1
76°
54°
2
66°
54°
3
66°
55°
4
67°
59°
5
68°
60°
6
74°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in South Boston Waterfront
South Boston Waterfront's May 2026 forecast shows daily high temperatures ranging from 56° to 93°, with overnight lows between 48° and 70°. The average high for May is 70° with an average low of 57°. 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 Waterfront. See also: June | July | August.