S
M
T
W
T
F
S
26
47°
40°
27
45°
37°
28
45°
36°
29
46°
37°
30
47°
43°
1
50°
43°
2
48°
42°
3
47°
40°
4
47°
42°
5
48°
40°
6
47°
39°
7
49°
41°
8
52°
44°
9
49°
43°
10
49°
42°
11
50°
45°
12
53°
45°
13
50°
44°
14
49°
42°
15
49°
40°
16
50°
42°
17
50°
44°
18
55°
46°
19
53°
46°
20
52°
45°
21
52°
44°
22
53°
44°
23
52°
47°
24
52°
46°
25
55°
45°
26
54°
46°
27
53°
47°
28
55°
47°
29
54°
46°
30
55°
45°
31
56°
43°
1
55°
42°
2
53°
47°
3
54°
44°
4
54°
43°
5
55°
44°
6
54°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Castleton
Castleton's May 2026 forecast shows daily high temperatures ranging from 45° to 56°, with overnight lows between 36° and 47°. The average high for May is 51° 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 Castleton. See also: June | July | August.
