Best Time for Scuba Diving on Koh Tao

2442 scuba diving beginners course
Scuba Diver Beginners Course

Why Koh Tao is Popular for Scuba Diving

Koh Tao is the scuba diving capital of South East Asia and certifies more divers than any other location in the world.

There are more than 50 scuba diving schools located across this small island offering PADI, SSI & RAID qualifications at some of the best diving course prices you can find. scuba diver koh tao
Amazing Marine Life on Koh Tao

Great Diving

However, don’t be put off by the cheaper price. Quality of service and training standards on Koh Tao are extremely high and the island has some of the most experienced Course Directors and trainers in the world.

With Koh Tao being so popular to learn to dive, diver and snorkeler safety is the number one priority, quickly followed by fun, adventure and lots of excitement. best scuba diving koh tao
Giant Puffer Fish Koh Tao

Explore The Coral Reefs around Koh Tao

The island is surrounded by over 8 kilometres of living coral reef, rock pinnacles and an incredibly diverse array of marine life, which makes it a great place to learn to dive.

There is a wide choice of great dive sites, ranging from shallow sites suitable for novice divers, to shipwrecks just waiting to be explored by experienced divers looking for a bit more adventure.

When people are planning their trip to Koh Tao, one of the first questions they usually ask is When is the best time for scuba diving on Koh Tao? sea turtles around koh tao
Marine Life & Turtles Koh Tao

Scuba Diving All Year Round on Koh Tao

With scuba diving possible all year round in consistently warm water, it can be difficult to provide a simple answer to the question.

Koh Tao is situated in the Gulf of Thailand at a location that provides a reasonable amount of shelter from adverse weather systems.

The weather is generally sunny and dry for the majority of the year, with temperatures ranging from 25-35C.

Wave heights and tides are relatively low and mild to none, which is great for scuba divers and underwater visibility can reach 30 metres on the best days. white rock dive site koh tao
Dive Site Koh Tao Banded Sea Krait

Warm Climate

The one time of year when the weather is not always the best for diving is during the monsoon season, which falls sometime during October and November.

With the monsoon weather can bring heavy rainfall and strong winds, the waves can be higher and visibility can be reduced. However, the temperature remains relatively warm so diving is still possible.

Monsoon does not mean it rains every day with high winds. Quite often it can consist of heavy rain showers, during the day or night, interspersed with sunshine or a calm evening. White Rock dive site koh tao turtle moray eel
Dive Site Koh Tao White Eyed Moray Eel

Best Time to Visit Koh Tao for Diving

With the knowledge that you can go scuba diving at any time of the year on Koh Tao, how do you decide when to visit?

The simplest answer is that it depends on what you are looking for. The weather and conditions change throughout the year and can have an impact on your experience below the water and on the land.

The most challenging conditions for diving occur during the end of October and November when Koh Tao experiences its monsoon season.

Stronger winds come in from the north east and can bring heavy rain with them so visibility underwater can drop below 5 metres. dive sites south west pinnacle koh tao blue spotted stingray
South West Pinnacle Dive Site Blue Spotted Ribbontail Stingray

25+ Dive Sites

However, as an island that is surrounded by dive sites, scuba diving schools can switch their schedule so that they visit the side of the island that is calm and protected.

The two main weather systems that affect Koh Tao are the north east monsoon and the south west monsoon. If the weather comes in from one direction, the diving will often take place on the opposite side of the island.

As you move out of the monsoon season into December, you enter the first of the high seasons that Koh Tao enjoys. Laem Thian dive site koh tao scribbled filefish
Laem Thian Dive Site Koh Tao Scribbled Filefish

Hot & Sunny Weather on Koh Tao

From mid December, January, February and into March, the whole island is normally thriving with visitors, which is ideal for meeting new people from around the world.

The weather starts to become much more dry and hot, although on occasions the monsoon rain can carry on into January.

The monsoon has been known to stretch into January so there is still the possibility of occasional rain showers and mountain run off, although generally the visibility will start to improve. White Rock dive site koh tao turtle giant grouper
White Rock Dive Site Koh Tao Giant Grouper

Hot Weather

The sea temperatures can be as low as 25C in January, but then it will start to warm up, although it is advisable to wear a wetsuit when diving.

In March and April Koh Tao experiences its hottest weather of the year. The sun shines almost every day and any rain usually falls in brief bursts, which can actually help to cool the air.
Whaleshark Koh Tao

The Best Time to see a Whaleshark on Koh Tao

The conditions underwater are possibly the best you will see, with temperatures between 29 and 31C and visibility reaching up to 30 metres.

Between Chinese holidays and outside of any European holiday periods, the island can be a little quieter during these months, which means there are fewer boats and divers in the water.


The reduced number of divers provides a more relaxing dive experience and makes it easier to explore the marine life the sea has to offer.

This is also a popular time for breeding of the smaller reef fish, so you get the opportunity to see large shoals of tiny fish and it is one of the best times to see a whaleshark. sail rock dive site koh tao rock formations
Sail Rock Dive Site Koh Tao Rock Formations

Diverse Marine Life

May and June is considered to be a low season on the Koh Tao, but the conditions are still great for scuba diving and snorkeling.

The sea tends to be flat, calm and the overall sea temperature is quite stable like the previous two months.

The winds are slightly stronger than you find in March & April and June sees a change of wind direction and it will start to arrive from a south-westerly direction, but this doesn’t affect the diving. dive sites south west pinnacle koh tao box fish
South West Pinnacle Dive Site Box fish

Lots of Activities & Things to do on Koh Tao

During July, August and into September, Koh Tao experiences its second busy period of the year.

The European holiday season falls during these months so the island gets busy again and there are lots of activities to get involved with, both in and out of the water.

The weather is still generally cooler than during March and April, plus the south-westerly breeze helps to keep the weather a little cooler. japanese gardens dive site koh tao fish species
Japanese Gardens Dive Site Koh Tao Fish Species

Good Conditions

The conditions under the water are good, with temperatures around 29C and visibility of up to 20 metres.

The dive boats tend to visit the dive sites on the east side of the island during these months as they are more sheltered from the south-westerly wind.

The south-westerly wind starts to calm down as you enter into September and the temperature cools both in and out of the water.

Visitor numbers start to fall as the European holiday season ends, so the dive sites around the island become quieter again. hawksbill turtle hin wong dive site koh tao
Turtle at Dive Site Koh Tao

Flexible Dive Boat Scheduling on Koh Tao

The diving conditions are still good, although the occasional storm can come from the East, bringing some rain and wind.

As you enter into October towards the monsoon season, the likelihood of seeing a whaleshark around Koh Tao increases again.

The winds from the north begin to pick up as the storms move in and the dive boats will begin to visit the south of the island more for protection.

No matter what time of the year you choose to visit Koh Tao, there are dive boats visiting the dive sites and you can enjoy diving all year round.

The conditions may not always be perfect, but with dive sites located all around the island, there is always great diving available. diving boat sunset koh tao
Diving Boat Sunset Koh Tao

Frequently Asked Questions

When is the best time to go diving on Koh Tao?

The best time for scuba diving on Koh Tao is at any time of year as the island enjoys year round scuba diving with warm sea temperatures.

As an island that is surrounded by dive sites, in the event of adverse weather coming in from the north east or south west, dive site selection is adapted accordingly.

The two main weather systems that can affect Koh Tao are the south west monsoon and the north east monsoon and both can be unpredictable and inconsistent.

What is the visibility like underwater on Koh Tao?

Koh Tao enjoys great visibility at most times of the year at many of the dive sites located around the island.

However, the visibility can vary from dive site to dive site on any given day and local dive groups try and report what it is like on a day to day basis.

As expected, visibility will change regularly and the weather and tidal influences have a role to play in how good or not so good visibility is.

Can you go diving in Monsoon season on Koh Tao?

Yes you can and diving is an activity that takes place every day on Koh Tao. North east Monsoon normally arrives around November, so the weather can become a little more unpredictable.

However, North East Monsoon can bring a little, a lot or no rain at all. The days during these months can be blazing hot sunshine with heavy rain showers through the night.

Sea temperatures tend to cool to around 24-25 degrees and air temperatures can be anything between 24-30 degrees.

Visibility can be from 2 metres to 20 metres with or without a thermocline at different dive sites at the same time. Unpredictable is the preferred description.

Do I have to wear a wetsuit diving Koh Tao?

Yes and No is the best answer. From October through to January, a wetsuit may be advisable to assist in keeping yourself relatively warm when diving.

Even though the water temperature may be 24 degrees, over the course of a dive of 45-60 minutes, without one you may start to feel a chill.

All Koh Tao dive centres provide shortie wetsuits for customers throughout the year and during the warmer months of January to September, board shorts may be all you need.


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