When is the best time to Scuba Dive on Koh Tao?

When is the best diving season on Koh Tao and what time of the year are Whale Sharks Sighted?


1000’s of people flock to Koh Tao every year to soak in some sun and live the island life. Koh Tao’s white sand and crystal clear waters make the island a must-see place in Thailand. Because of these crystal clear waters Koh Tao has become famous amongst Scuba Divers worldwide and is regarded as one of the best places in the world to learn to Scuba Dive.

Because of Koh Tao’s many easily accessible dive sites, generally calm water, great visibility and diverse marine life over 50 dive schools populate the island making the price very affordable for any traveller’s budget and is the cheapest place in the world to get SCUBA certified.

The Open Water Diver Course is the most popular choice and will turn a complete beginner into a competent scuba diver certified to Scuba Dive to 18m in just 3 and a half days. One-day experience dives and fun dives for already certified divers are also easy to find on Koh Tao.

Koh Tao Dive Sites with Phoenix Divers

Koh Tao Diving Seasons & the best time to Scuba Dive on Koh Tao


We are very lucky to have over 20 Dive sites spread around the whole island. This means there is always somewhere that will have calm water on Koh Tao and because of this the diving is all year round and it is very rare that courses or diving trips are cancelled or postponed.

Visibility of around 10-20 meters and calm water starts the year off in a good way.

Generally the best and hottest months of the year to visit due to Koh Tao’s dry season. The weather is almost guaranteed to be great, blue skies, sun shine and no rain. The diving follows the trend and visibility should be great with Whale Sharks around!

The weather should cool down a little bit and the wind might pick up but it shouldn’t affect the diving too much – the dive sites we visit may have to be a bit more selective to avoid the wind and waves.

The visibility is normally great in these months and can sometimes hit 30+ meters. Our favourite dive site Chumphon Pinnacle normally attracts lots of big fish including Whale Sharks and these months are some of the best to Scuba Dive on Koh Tao.

The island really quiets down during these months and the diving conditions aren’t quite as nice as July-September but there can still be some good diving and the conditions are still great for learning – group sizes are normally nice and small during this month.

During November Koh Tao will enter ‘Monsoon season’. Don’t worry it’s not as scary as it sounds, monsoon season usually brings at least one rain shower per day – normally for around an hour but diving courses at Phoenix Divers will start almost every day and visibility is still quite good (8-15 meters).

The island will remain quiet for the first half of the month and the weather usually improves throughout the month.  By mid-December the island will start to fill up with holiday-goers coming for Christmas and New Years. Visibility normally improves with the weather as the month goes on.

Whale Sharks, sightings and the best time to see these gentle giants on Koh Tao

The Whale Shark is the biggest fish in the world. This slow-moving filter-feeder can grow up to 12m and is on every Scuba Divers ‘to-see’ list. These giants prefer warm waters and they populate all tropical seas including Australia, Indonesia and of course Thailand & Koh Tao. The Whale Shark is a docile fish and we tend to get smaller ones here on Koh Tao, normally between 2 & 5 meters.

Whale Sharks visit Koh Tao all year round but tend to visit more in March & April and also in November when the water has more algae for them to eat – so book your diving course and cross your fingers!