Rule #1: Match Your Island Coast to Your Travel Month
- November – April (Northeast Dry Season): Best time for the Andaman Sea (Phuket, Krabi/Railay, Koh Phi Phi, Koh Lanta, Koh Lipe, Similan Islands) AND the Eastern Trat Archipelago (Koh Chang, Koh Mak, Koh Kood).
- May – September (Southwest Summer Monsoon): While the Andaman Coast experiences monsoon swells and Similan/Maya Bay seasonal closures, the Lower Gulf Islands (Koh Samui, Koh Phangan, Koh Tao) are sheltered by the southern peninsula and enjoy warm, sunny beach and diving weather all summer long!
Calculate exact catamaran, speedboat, and national park costs in our Andaman & Gulf Island Ferry + Park Fee Calculator.