Thailand in May 2026: Weather, Events, and Where to Go

May is the beginning of Thailand's low season in the Andaman coast and south, while the north sees the final dry days before the rainy season. It is a month of contrasts — some areas are at their greenest and most atmospheric, prices fall significantly, and crowds thin out. May weather by region: Bangkok and Central Thailand: hot and humid (33–36°C), with increasing afternoon thunderstorms as the month progresses. Not ideal for outdoor sightseeing in the midday heat but comfortable in the evenings. April and May are Bangkok's hottest months. Chiang Mai and North Thailand: end of dry season transitioning to early rains. Temperatures cool slightly from the April peak (27–32°C). Rice paddies begin to green. Pai and the mountains see early mists. Still pleasant for trekking early in the month. Andaman Coast (Phuket, Krabi, Koh Lanta, Phi Phi): monsoon arrives May–June. May sees increasingly rough seas, some beach closures, and regular heavy rain. Phuket and Krabi are still partially operational but beach conditions are patchy. Many speedboat routes reduce frequency. Hotel prices drop 30–50% from high season. Gulf of Thailand (Koh Samui, Koh Phangan, Koh Tao): excellent conditions in May — the Gulf is in its own dry cycle. Koh Samui in May is actually one of its best months: clear water, manageable crowds, not yet rainy season (which hits October–November). Koh Phangan full moon party: May date varies (check the calendar); the beach party continues through shoulder season. Best destinations in May: the Gulf islands (Koh Samui, Phangan, Tao) for beaches. Bangkok for culture and food. Chiang Mai for a slower, cooler northern experience. Budget advantage: May hotel prices in Phuket and Koh Samui can be 30–50% below December highs. Even premium resorts offer deals. Flights are cheaper; tourist sites are less crowded. Songkran aftermath: if you missed April's Songkran water festival, Chiang Mai still has a more relaxed festive atmosphere in early May.