Koh Phangan is warm all year, but the season you pick changes the trip — drier months bring calmer seas and busier beaches, the wetter stretch brings short afternoon showers and quieter roads. Here's how to think about timing your visit to Haad Yao Beach.
Dry season — roughly December to April
This is the busiest and most reliably sunny stretch of the year on the Gulf of Thailand side of Thailand, which is where Koh Phangan sits. Expect the beach at its calmest, good visibility for snorkelling and SUP off Haad Yao, and higher demand for rooms — booking ahead matters more in this window.
Green season — roughly May to November
Rain tends to come in shorter afternoon or evening bursts rather than all day, and the island is noticeably quieter. If you don't mind the occasional shower, this is when you'll find the beach closest to empty and rates generally easier.
Late October and November can bring the heavier rain of the year for the Gulf coast — worth checking closer to your dates if you're travelling then.
Planning around Full Moon Party
Full Moon Party happens on Haad Rin beach roughly once a month, tied to the lunar calendar rather than a fixed date — and a handful of 2026 dates are officially shifted to avoid Buddhist holy days. If you want to catch it (or deliberately avoid the crowds it brings), check the confirmed dates before booking.