S
M
T
W
T
F
S
26
99°
77°
27
99°
77°
28
98°
77°
29
98°
77°
30
98°
77°
1
98°
76°
2
98°
79°
3
96°
77°
4
94°
77°
5
93°
77°
6
96°
78°
7
96°
78°
8
97°
76°
9
95°
75°
10
92°
76°
11
95°
75°
12
91°
76°
13
97°
76°
14
93°
76°
15
91°
75°
16
90°
74°
17
93°
69°
18
89°
80°
19
93°
78°
20
90°
79°
21
91°
79°
22
91°
80°
23
92°
80°
24
89°
81°
25
88°
82°
26
89°
81°
27
91°
79°
28
92°
80°
29
91°
79°
30
92°
80°
31
88°
81°
1
87°
82°
2
87°
83°
3
88°
83°
4
87°
84°
5
87°
83°
6
88°
83°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Ko Samui
Ko Samui's May 2026 forecast shows daily high temperatures ranging from 87° to 93°, with overnight lows between 78° and 84°. The average high for May is 90° with an average low of 81°. 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 Ko Samui. See also: June | July | August.
