S
M
T
W
T
F
S
26
66°
31°
27
74°
33°
28
73°
41°
29
60°
51°
30
51°
42°
1
54°
32°
2
50°
34°
3
56°
37°
4
68°
43°
5
72°
47°
6
47°
42°
7
55°
39°
8
56°
38°
9
67°
30°
10
59°
43°
11
54°
34°
12
57°
32°
13
51°
43°
14
57°
46°
15
62°
49°
16
73°
49°
17
76°
55°
18
86°
50°
19
82°
67°
20
72°
50°
21
59°
39°
22
68°
33°
23
69°
40°
24
60°
51°
25
72°
53°
26
82°
54°
27
75°
56°
28
67°
52°
29
66°
46°
30
63°
44°
31
66°
45°
1
67°
46°
2
73°
47°
3
73°
53°
4
82°
55°
5
80°
58°
6
74°
52°
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 63° to 82°, with overnight lows between 44° and 58°. The average high for May is 71° with an average low of 50°. 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.
