S
M
T
W
T
F
S
26
62°
37°
27
66°
36°
28
56°
41°
29
51°
44°
30
53°
45°
1
62°
41°
2
53°
44°
3
52°
38°
4
64°
48°
5
69°
52°
6
62°
50°
7
59°
39°
8
55°
38°
9
57°
45°
10
58°
42°
11
59°
43°
12
61°
44°
13
57°
46°
14
58°
44°
15
62°
46°
16
61°
44°
17
61°
42°
18
62°
49°
19
62°
49°
20
62°
48°
21
66°
50°
22
70°
47°
23
61°
46°
24
62°
50°
25
64°
46°
26
65°
47°
27
64°
47°
28
63°
49°
29
64°
51°
30
67°
52°
31
65°
49°
1
65°
45°
2
64°
46°
3
66°
48°
4
65°
47°
5
65°
47°
6
66°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in New Castle
New Castle's May 2026 forecast shows daily high temperatures ranging from 52° to 70°, with overnight lows between 38° and 52°. The average high for May is 62° with an average low of 46°. 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 New Castle. See also: June | July | August.
