English (United Kingdom)

Koh Tao is fortunate that thanks to its location and geography you can dive ALL YEAR round with two types of season: weather and tourist.

Weather forecast on Koh Tao

Conditions are usually favorable from mid-December with temperature and visibility increasing and flat seas until April-May.

May to August can bring changing weather which can include slight showers and windy periods but overall conditions are good. Between the months of September and October conditions re-peak with good visibility and flat seas.

Koh Tao and the Gulf of Thailand has its SE Monsoon usually in November and December with heavy rain at times. Conditions are the worst this time of the year all over the South of Thailand. 


The island starts to fill just before Christmas and continues up until the end of April.

There is a second period where the island fills again around about mid-July until the end of September. If you would like to dive during the busier periods we strongly advise that you make a reservation for a bungalow as there is still a shortage of accomodation on Koh Tao. Especially budget rooms are hard to find for late deciders.


Thanks to the location and geography for Koh Tao, you can dive all year round. There are 27 dive sites to choose from so plenty of alternatives to find sheltered areas.

During the SE Monsoon season in November-December the visibility is at its worst, ranging from 5-10 meters. It gradually improves in January and from then on you can count on 30+ meters.

The deeper dive sites are spectacular as you will be able to see from the bottom (30 meters) all the way to the surface.


Docile whale sharks on Koh TaoFor many divers whale sharks are the ultimate experience and for many divers this ultimate experience comes true on Koh Tao.

Although whale sharks are seasonal, they also have spotted out side the so called whale shark season.

You will have a higher chance of diving next to one of these friendly giants from February till May and from August till November.

For about 2 years now, the whale shark  population is being monitored on Koh Tao and all sightings are reported in the data base of Marine Conservation Koh Tao.

Data collection is very important to be able to see declines or problems in existing populations to encourage countries in the region to take measures to protect this magnificent animals for the future. Believe it or not, whale sharks are now also being targeted by the Shark Fining Industry which is responsible for the death of a staggering 100 million sharks per year !

Sharks keep the oceans healthy as part of the natural food chain.  Humanity is damaging this fine balance through fishing and fining of sharks, some species are now close to extinction.  This will cause huge problems to our ecosystem if left unchecked.

To learn how to help please check out the following sites, every little bit counts.




Koh Tao is one of the few islands in the world, that only has one tide (Diurnal tide) a day. Due to this unique feature the island doesn't suffer the same amount of tidal exchange that is common on the Andaman side (West cost) of Thailand.

This results in safe and calm diving conditions without strong and dangerous currents.

The only time that the island experiences any form of current is around the dates of the full- and black moons, but they hardly pose a problem, not even for novice divers.
Relaxing on the sun roof of the boatLocals would say that Koh Tao is always warm, other tourists may feel that it is hot.

Air temperatures rarely drop below 30 degrees, except in the monsoon season, where they can plummet to 28 degrees. Because the sea is never far away, even on hot days a gentle breeze helps cooling of a bit, a plunge in the sea can further alleviate the heat.

Water temperatures normally stay around 27/31 degrees, a perfect temperature to enjoy the under water world and all its colorful inhabitants.

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