While Phuket has tropical weather—and plenty of visitors—year-round, it officially has three distinct tourism seasons. The high season is November to February, when temperatures are the coolest of the year, though it’s still pretty warm with temps in high 80s and low 90s. The beach and ocean conditions are at their calmest, and rainfall is at the lowest levels of the year. Beaches and hotels throughout the island are packed with visitors, and accommodation prices will be at their highest.
From May to September, Phuket is buffeted by monsoon rains that can flood the streets, stir up offshore visibility, and make the western beaches unsafe for swimming. However, the rains can help drop the hot summer temperatures slightly, and visitors can find decent discounts on accommodations and activities.
The shoulder season months are April and May and October. The spring shoulder season can bring price reductions in hotels, and the weather is usually dry, although hot. October is the tail end of the rainy season, but it can be a good time for visitors looking to beat the incoming high season crowds.
October is also when Phuket locals celebrate Vegetarian Festival, an event notable not just for the types of food eaten but by the ceremonies that accompany it. These celebrations are marked by apparently pain-impervious adepts who pierce their tongues and cheeks with spikes and swords while parading through the streets in trance-like states.