S
M
T
W
T
F
S
26
55°
46°
27
57°
47°
28
56°
45°
29
54°
46°
30
55°
45°
1
56°
48°
2
57°
46°
3
56°
42°
4
55°
43°
5
55°
42°
6
57°
42°
7
59°
46°
8
60°
50°
9
62°
50°
10
63°
46°
11
60°
44°
12
57°
45°
13
58°
45°
14
60°
48°
15
61°
46°
16
62°
47°
17
62°
47°
18
63°
52°
19
64°
48°
20
64°
49°
21
65°
52°
22
67°
52°
23
67°
55°
24
66°
56°
25
73°
56°
26
72°
55°
27
67°
57°
28
73°
57°
29
77°
52°
30
71°
52°
31
69°
54°
1
68°
53°
2
71°
52°
3
72°
59°
4
78°
59°
5
79°
58°
6
78°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Dartmouth
Dartmouth's May 2026 forecast shows daily high temperatures ranging from 54° to 79°, with overnight lows between 42° and 59°. The average high for May is 64° with an average low of 50°. 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 Dartmouth. See also: June | July | August.