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
60°
42°
9
56°
51°
10
71°
51°
11
55°
46°
12
60°
43°
13
61°
50°
14
56°
50°
15
60°
48°
16
65°
53°
17
66°
52°
18
67°
53°
19
68°
57°
20
69°
56°
21
72°
52°
22
63°
49°
23
63°
50°
24
64°
55°
25
66°
56°
26
71°
57°
27
71°
53°
28
67°
50°
29
65°
53°
30
68°
55°
31
73°
58°
1
72°
58°
2
68°
57°
3
70°
58°
4
73°
59°
5
73°
60°
6
75°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Downtown Boston
Downtown Boston's May 2026 forecast shows daily high temperatures ranging from 55° to 75°, with overnight lows between 42° and 60°. The average high for May is 66° with an average low of 53°. 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 Downtown Boston. See also: June | July | August.
