S
M
T
W
T
F
S
26
58°
44°
27
59°
44°
28
60°
43°
29
60°
42°
30
56°
39°
1
56°
40°
2
55°
41°
3
53°
38°
4
52°
40°
5
54°
38°
6
52°
38°
7
52°
39°
8
53°
39°
9
53°
40°
10
54°
39°
11
54°
44°
12
55°
44°
13
59°
45°
14
56°
43°
15
55°
40°
16
57°
44°
17
56°
44°
18
56°
45°
19
57°
44°
20
56°
43°
21
56°
44°
22
57°
43°
23
56°
44°
24
57°
46°
25
57°
46°
26
58°
45°
27
57°
46°
28
57°
45°
29
58°
45°
30
59°
46°
31
58°
46°
1
62°
47°
2
64°
47°
3
63°
43°
4
62°
45°
5
63°
46°
6
63°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Dumbarton
Dumbarton's May 2026 forecast shows daily high temperatures ranging from 52° to 64°, with overnight lows between 38° and 47°. The average high for May is 57° with an average low of 43°. 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 Dumbarton. See also: June | July | August.
