S
M
T
W
T
F
S
29
63°
27°
30
69°
45°
31
83°
50°
1
84°
59°
2
82°
55°
3
83°
59°
4
84°
58°
5
69°
48°
6
66°
40°
7
62°
45°
8
57°
33°
9
65°
35°
10
81°
55°
11
79°
49°
12
79°
59°
13
82°
57°
14
84°
61°
15
88°
60°
16
86°
58°
17
85°
55°
18
78°
50°
19
70°
49°
20
68°
49°
21
75°
52°
22
77°
56°
23
78°
42°
24
74°
49°
25
73°
48°
26
71°
46°
27
66°
42°
28
65°
42°
29
71°
44°
30
71°
48°
1
72°
51°
2
73°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
April Weather in New Castle
New Castle's April 2026 forecast shows daily high temperatures ranging from 65° to 88°, with overnight lows between 42° and 61°. The average high for April is 76° 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 April weather will actually feel in New Castle. See also: May | June | July.