S
M
T
W
T
F
S
26
54°
46°
27
59°
46°
28
55°
46°
29
63°
45°
30
64°
48°
1
54°
50°
2
55°
50°
3
59°
46°
4
57°
45°
5
55°
46°
6
52°
43°
7
55°
41°
8
57°
50°
9
57°
45°
10
55°
41°
11
50°
43°
12
55°
43°
13
54°
46°
14
54°
46°
15
53°
45°
16
53°
44°
17
55°
45°
18
54°
50°
19
56°
51°
20
59°
52°
21
58°
53°
22
62°
53°
23
66°
53°
24
65°
53°
25
67°
52°
26
66°
54°
27
62°
51°
28
61°
50°
29
60°
49°
30
56°
51°
31
57°
52°
1
56°
52°
2
57°
51°
3
57°
53°
4
58°
53°
5
59°
54°
6
59°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Castletown
Castletown's May 2026 forecast shows daily high temperatures ranging from 54° to 67°, with overnight lows between 45° and 54°. The average high for May is 60° with an average low of 52°. 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 Castletown. See also: June | July | August.
