S
M
T
W
T
F
S
26
79°
61°
27
66°
50°
28
77°
48°
29
81°
59°
30
77°
63°
1
70°
59°
2
63°
50°
3
72°
45°
4
79°
51°
5
78°
59°
6
85°
70°
7
79°
58°
8
71°
55°
9
80°
61°
10
83°
66°
11
78°
63°
12
79°
62°
13
82°
61°
14
82°
61°
15
86°
62°
16
85°
61°
17
87°
71°
18
80°
62°
19
79°
62°
20
85°
63°
21
83°
63°
22
80°
58°
23
79°
57°
24
78°
58°
25
80°
61°
26
80°
61°
27
81°
59°
28
80°
60°
29
80°
62°
30
82°
63°
31
81°
64°
1
82°
66°
2
84°
65°
3
82°
66°
4
82°
66°
5
83°
67°
6
84°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Dorchester
Dorchester's May 2026 forecast shows daily high temperatures ranging from 71° to 87°, with overnight lows between 51° and 71°. The average high for May is 81° with an average low of 62°. 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 Dorchester. See also: June | July | August.