S
M
T
W
T
F
S
26
59°
46°
27
61°
47°
28
59°
45°
29
57°
44°
30
58°
44°
1
61°
44°
2
61°
40°
3
62°
41°
4
66°
50°
5
67°
50°
6
62°
47°
7
62°
46°
8
68°
46°
9
63°
47°
10
65°
53°
11
73°
51°
12
65°
48°
13
66°
54°
14
75°
54°
15
67°
49°
16
66°
48°
17
68°
52°
18
73°
56°
19
75°
52°
20
75°
48°
21
66°
47°
22
68°
52°
23
68°
49°
24
72°
55°
25
77°
58°
26
79°
57°
27
70°
55°
28
70°
58°
29
72°
58°
30
71°
57°
31
71°
59°
1
80°
60°
2
78°
59°
3
79°
59°
4
80°
60°
5
79°
58°
6
81°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Gwynedd
Gwynedd's May 2026 forecast shows daily high temperatures ranging from 57° to 81°, with overnight lows between 40° and 60°. The average high for May is 69° with an average low of 51°. 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 Gwynedd. See also: June | July | August.