30°C / 86°F
The measurements for the sea temperature in Ko Samui, Surat Thani are provided by the daily satellite readings provided by the NOAA. The temperatures given are the surface temperature (SST) which is most relevant to recreational users.
These average ocean temperatures for Ko Samui are calculated from several years of archived data.
Whilst sea temperatures for Ko Samui are as accurate as current data allows there may be slight local and regional variations depending on conditions. Time of day and wind direction may have a temporary local effect as can water flows from neraby rivers.