S
M
T
W
T
F
S
29
41°
31°
30
59°
29°
31
52°
38°
1
43°
32°
2
46°
32°
3
67°
38°
4
51°
36°
5
43°
32°
6
41°
24°
7
33°
18°
8
37°
29°
9
51°
40°
10
51°
34°
11
51°
35°
12
55°
47°
13
60°
45°
14
52°
31°
15
53°
39°
16
54°
37°
17
54°
38°
18
53°
35°
19
50°
42°
20
58°
41°
21
55°
42°
22
52°
42°
23
58°
44°
24
59°
39°
25
49°
36°
26
49°
37°
27
50°
37°
28
52°
40°
29
51°
37°
30
50°
39°
1
51°
38°
2
51°
35°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
April Weather in Castleton
Castleton's April 2026 forecast shows daily high temperatures ranging from 33° to 60°, with overnight lows between 18° and 47°. The average high for April is 51° with an average low of 37°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how April weather will actually feel in Castleton. See also: May | June | July.