A fair question, and one that regularly comes up in our email correspondence with customers who are planning their trips to make the most of the best of Koh Tao weather. Its also becoming an increasingly difficult question to answer however, as weather patterns have been changing quite a bit in recent years.
The first thing to explain is that the weather system in Thailand is extremely regionalised. Thailand stretches over a long distance running North to South, and the climate does vary quite a bit because of this, with different areas experiencing their wet seasons at different times. The country is also surrounded by different oceans on each side – the Andaman Sea to the West, and the Gulf of Thailand to the East, and is affected by different weather systems accordingly. So if you are travelling around other areas in Thailand too during your stay, then do be prepared for different conditions in the various locations you are visiting.
On the West Coast for example (Phuket, Krabi, Koh Lanta, Koh Phi Phi, Koh Lanta etc) the monsoon comes in June through to August. So while it is usual on Koh Tao to experience some sporadic rainfall during these months from the spillover effect of the monsoon that is hitting the West Coast, it’s usually just for an hour or two at a time.
The monsoon season on Koh Tao normally arrives in November, and in the past by mid December the sunny skies have been back in force. However, our monsoon is becoming very difficult to predict with accuracy, as the seasons have been changing so much in recent years due to climate change. So in the last couple of years monsoon has been delayed and did not arrive until December/January. If and when monsoon does come (some years it just doesn’t, and some years isn’t as powerful as it used to be) you can expect rains and high winds.
Diving conditions during monsoon are affected with choppy surface conditions and reduced visibility, although its actually a pretty cool sight to look up from underwater and see the raindrops hitting the surface. If you are after a challenge and are keen on becoming a more experienced diver these are great conditions to dive in! This is specially for those taking pro level courses – in terms of becoming a confident and competent PADI professional, it’s actually a great time to train! Plus with your training being completed in low season, it would mean you were finished and available to work when high season starts if that’s something you were looking to do.
If you’d like to know more details about weather and conditions both above and below the surface on a monthly basis, feel free to check out our previous blog post on diving conditions throughout the year 🙂