The average temperature of the water in the Similan Islands in October is about 29°C, or 84°F.
October 2023 saw a drop in that temperature, against the historical norm. The very lowest temperature recorded on a dive was 24°C by our team, although that is not expected again going forward.
In detail:
The sea water temperature in the Similan Islands is usually stable at 29°C or 84°F in October.
The historic average October water temperature for the Similan Islands is 29°C, ranging from 27.7°C to 29.9°C.
Other sources also confirm that during October, the average water temperature in the Similan Islands holds at approximately 28-29°C (82-84°F).