S
M
T
W
T
F
S
26
59°
44°
27
58°
41°
28
61°
42°
29
60°
40°
30
59°
40°
1
61°
44°
2
62°
41°
3
61°
42°
4
63°
46°
5
71°
51°
6
72°
46°
7
66°
46°
8
73°
53°
9
74°
54°
10
75°
52°
11
67°
46°
12
63°
45°
13
65°
47°
14
65°
48°
15
66°
52°
16
65°
51°
17
66°
51°
18
77°
47°
19
69°
48°
20
72°
49°
21
70°
48°
22
69°
47°
23
68°
48°
24
69°
48°
25
70°
51°
26
71°
51°
27
72°
52°
28
72°
51°
29
73°
60°
30
73°
52°
31
80°
52°
1
73°
59°
2
74°
56°
3
79°
53°
4
76°
58°
5
80°
54°
6
76°
55°
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 58° to 80°, with overnight lows between 40° and 60°. The average high for May is 69° with an average low of 49°. 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.