The Phuket Vegetarian Festival runs for nine days each year, beginning on the first evening of the ninth lunar month (typically October). It is a Taoist festival of Chinese origin, dedicated to the Nine Emperor Gods, and it involves rituals of purification: participants follow a strict vegetarian diet, dress in white, and the most devoted act as spirit mediums, performing acts of extreme devotion — walking on hot coals, climbing ladders of blades, and piercing their cheeks and tongues with skewers and other objects — believed to be proof of divine possession.
The street processions are the most spectacular part: mediums in trance states are carried through the streets of the old town on palanquins, accompanied by firecrackers, drum corps, and crowds of thousands. The atmosphere is intense and unlike anything else in Thailand. It is loud, densely crowded, and not for the squeamish — but it is one of the most extraordinary public religious events in Southeast Asia. If your travel dates are flexible and you have any interest in folk religion or spectacular spectacle, time your Phuket visit around it.