Thailand is one of the few countries you would want to return to again and again. Since it is a large country, the weather varies in different regions. However, speaking of Phuket the best time is between November and March. During this period the high season takes place, the sea is warm and calm and the water temperature rises up to around 27 degrees. In comparison Koh Samui experiences the rainy season during the same period, with good weather only starting in January and continuing until March. In April, a very hot period begins in Koh Samui. However, this time frame is still loved by many tourists because the prices drop. Generally due to global climate change, seasons are shifting everywhere, so you might encounter perfect weather during the low season or conversely, the opposite. We live in a changing world and everything changes so fast.