S
M
T
W
T
F
S
26
48°
26°
27
53°
24°
28
59°
32°
29
52°
32°
30
54°
36°
1
50°
41°
2
59°
42°
3
52°
36°
4
58°
33°
5
73°
41°
6
69°
51°
7
55°
39°
8
54°
33°
9
59°
33°
10
63°
45°
11
60°
46°
12
46°
38°
13
58°
38°
14
67°
45°
15
51°
43°
16
72°
43°
17
74°
49°
18
58°
46°
19
68°
47°
20
82°
44°
21
52°
38°
22
52°
33°
23
53°
33°
24
70°
43°
25
60°
48°
26
59°
43°
27
51°
42°
28
45°
38°
29
44°
38°
30
44°
37°
31
51°
35°
1
58°
44°
2
62°
44°
3
66°
46°
4
67°
49°
5
74°
53°
6
70°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Cornwall
Cornwall's May 2026 forecast shows daily high temperatures ranging from 44° to 74°, with overnight lows between 35° and 53°. The average high for May is 58° 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 Cornwall. See also: June | July | August.
