S
M
T
W
T
F
S
26
63°
46°
27
61°
46°
28
64°
43°
29
66°
41°
30
57°
50°
1
63°
52°
2
59°
50°
3
61°
48°
4
59°
50°
5
55°
46°
6
59°
39°
7
57°
45°
8
59°
46°
9
59°
41°
10
59°
36°
11
59°
46°
12
57°
48°
13
55°
48°
14
54°
43°
15
55°
41°
16
57°
46°
17
54°
43°
18
55°
41°
19
59°
52°
20
63°
54°
21
64°
57°
22
64°
52°
23
68°
48°
24
75°
52°
25
82°
50°
26
88°
55°
27
86°
61°
28
66°
57°
29
70°
55°
30
64°
55°
31
66°
58°
1
65°
51°
2
60°
52°
3
60°
49°
4
56°
47°
5
59°
48°
6
59°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Castleisland
Castleisland's May 2026 forecast shows daily high temperatures ranging from 56° to 66°, with overnight lows between 47° and 58°. The average high for May is 61° with an average low of 51°. 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 Castleisland. See also: June | July | August.
