Southeast Asia, by the calendar

Most travel advice for this region is organised by place: what to see in Hoi An, what to do in Chiang Mai. This guide is organised by date. It starts from the things that only happen at a certain time of year or on a certain night of the moon, and works out when they fall in 2026 and 2027, how reliable that date is, and what a traveller needs to do differently to catch them.

Three kinds of date run through the region. Some are fixed by government decree, such as Songkran in Thailand or the Khmer New Year holiday in Cambodia. Some move every year with the lunar calendar, such as Tet, the Hoi An lantern nights, Loi Krathong and the Cambodian Water Festival. And some are set by nature, which means a window of a few weeks rather than a day: rice ripening on the terraces, buckwheat flowering on the Dong Van plateau, fireflies in a national park forest. Each needs a different kind of planning, and the pages below say which kind you are dealing with.

The festival pages give the 2026 and 2027 dates, say whether each date is official, announced or only calculated from the moon, and describe what actually happens on the night.

• Festival dates for 2026 and 2027 — one table for Tet, Mid-Autumn, the end of Buddhist Lent, Pchum Ben, the Water Festival, Loi Krathong and the April new year holidays, with how each date is set.
• Hoi An full-moon lantern nights — every 14th day of the lunar month through 2027, the lights-off time, the ticket and the flood months.
• Loi Krathong and Yi Peng — why sources disagree on the 2026 night, the no-lantern zones in Chiang Mai and the evening flight cuts at its airport.
• Songkran, Pi Mai Lao and Khmer New Year — three countries on holiday in the same week, in the hottest weather of the year.

A dated event changes the economics of a trip. Flights, rooms and transfers are priced against demand, and demand for a famous night can be far above normal. The planning page covers booking windows, spare days and what to do when a date has not been announced yet.

The when-not-to-go page is the other half: the smoke season in the north of Thailand and Laos, typhoons and floods on the Vietnamese coast, the hottest weeks at Angkor, and the holidays when transport is full and businesses close. Sometimes the right answer is a different month.

• Travellers looking to book a tour, a ticket or a room. This guide sells nothing and takes no bookings.
• Readers who want a full guide to one city. We cover the event and the season, not every sight in town.
• Anyone who wants a list of favourites. We describe what happens and when; we do not rank places or events.
• People who need certainty that a festival will go ahead. Weather and official decisions can change or cancel events, and we say so where it has happened.