A handful of dates shape the island's calendar and are worth knowing before you book — some make for a livelier trip, others are worth planning around rather than into.
Songkran (mid-April)
Thailand's New Year, marked nationwide by the country's famous water fights — expect main streets in tourist areas to turn into full-scale water battles for several days, typically 13–15 April. Waterproof your phone and valuables before heading out, and expect many shops and some restaurants in tourist zones to close or run reduced hours around the main days.
Phuket Vegetarian Festival (September/October)
A nine-day Taoist festival rooted in Phuket's Chinese immigrant community, best known outside Thailand for its startling street processions featuring devotees — spirit mediums known locally as "mah song" — in trance, performing acts of self-mortification with skewers and blades. Alongside the processions, the entire town fills with vegetarian food stalls marked with yellow flags, and participants are expected to dress in white and avoid meat, alcohol and strong-smelling foods for the festival's duration. The tradition traces back to a 19th-century Chinese opera troupe in Kathu whose illness was said to be cured by a strict vegetarian diet and ritual observance — the origin story still told to explain the festival today. It's an intense event to watch rather than a casual spectacle; standing well back from the procession route is standard visitor etiquette.
Por Tor — the Hungry Ghost Festival (August/September)
A quieter, far less-visited Hokkien Chinese tradition than the Vegetarian Festival, centred on Phuket Town's Chinese shrines during the seventh lunar month. Families believe the gates of the underworld open during this period, and lay out offerings — including stacks of bright red, turtle-shaped rice cakes called ang ku — both for their own ancestors and for wandering spirits with no family to feed them. The main shrine, Seng Tek Bel (also called Por Tor Kong Shrine) in the Bang Niew area of Phuket Town, runs the fullest program of ceremonies; the nearby Ranong Road market area is also worth a look during the festival period. It's a genuine local observance rather than a tourist event, so modest dress and quiet, respectful observation from a distance are expected.
Chinese New Year (January/February)
Old Phuket Town's large Chinese community marks Chinese New Year with lion dances, lantern displays and busy shrine visits — the Old Town shophouse district is the best place to see it, with a noticeably festive atmosphere along Thalang and the surrounding streets in the days around the new moon.
Loy Krathong (November)
A nationwide festival where small floating offerings (krathong), traditionally made from banana leaf and flowers, are released onto water after dark — a striking, low-key evening compared to Songkran's chaos, and one of the more photogenic nights to be on the island.