S
M
T
W
T
F
S
26
56°
41°
27
56°
41°
28
57°
38°
29
62°
36°
30
61°
33°
1
65°
30°
2
71°
33°
3
75°
35°
4
70°
45°
5
66°
40°
6
55°
35°
7
70°
29°
8
78°
37°
9
76°
45°
10
79°
44°
11
85°
54°
12
91°
43°
13
90°
45°
14
83°
44°
15
84°
51°
16
77°
46°
17
70°
41°
18
59°
36°
19
64°
37°
20
71°
40°
21
74°
42°
22
81°
48°
23
77°
49°
24
73°
46°
25
77°
47°
26
79°
48°
27
76°
40°
28
69°
36°
29
69°
37°
30
71°
38°
31
78°
43°
1
80°
44°
2
81°
45°
3
82°
48°
4
83°
49°
5
82°
46°
6
79°
46°
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 59° to 84°, with overnight lows between 36° and 51°. The average high for May is 76° with an average low of 44°. 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.
