S
M
T
W
T
F
S
26
63°
51°
27
70°
44°
28
65°
44°
29
67°
54°
30
71°
53°
1
66°
44°
2
59°
45°
3
64°
42°
4
77°
44°
5
82°
55°
6
73°
63°
7
68°
50°
8
70°
45°
9
74°
50°
10
83°
55°
11
63°
43°
12
72°
40°
13
78°
46°
14
68°
49°
15
73°
46°
16
85°
57°
17
95°
79°
18
95°
70°
19
97°
68°
20
95°
68°
21
91°
59°
22
61°
57°
23
59°
54°
24
74°
65°
25
75°
66°
26
78°
65°
27
81°
65°
28
84°
62°
29
78°
57°
30
71°
55°
31
70°
52°
1
72°
55°
2
77°
55°
3
78°
58°
4
80°
60°
5
80°
60°
6
79°
59°
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 70° to 84°, with overnight lows between 52° and 66°. The average high for May is 77° with an average low of 60°. 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.
