S
M
T
W
T
F
S
26
63°
34°
27
73°
36°
28
72°
46°
29
71°
50°
30
52°
41°
1
55°
36°
2
52°
36°
3
49°
36°
4
69°
44°
5
78°
55°
6
55°
42°
7
58°
34°
8
53°
32°
9
54°
31°
10
65°
38°
11
56°
31°
12
56°
31°
13
58°
40°
14
57°
47°
15
63°
48°
16
73°
49°
17
78°
48°
18
83°
65°
19
86°
68°
20
77°
41°
21
59°
38°
22
63°
47°
23
63°
49°
24
65°
48°
25
68°
49°
26
64°
52°
27
67°
48°
28
69°
52°
29
71°
54°
30
73°
56°
31
67°
53°
1
69°
52°
2
67°
53°
3
67°
51°
4
66°
55°
5
69°
55°
6
73°
54°
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 59° to 86°, with overnight lows between 38° and 68°. The average high for May is 70° with an average low of 52°. 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.
