Phuket has a tropical climate, warm all year and with monsoons during the wet season. Phuket offers good weather just about any time of the year in between rain. Humidity is a factor throughout the year, but less so in the high season, when there is less rain.
It is often said that there are two seasons in Phuket: Wet and Dry. This is not completely accurate, since it can rain at any time of the year. Most rain, when it comes, is heavy and often only lasts for a minute or two. In between rains, the sky is usually blue.
The high season for tourists falls between November and March, which tends to be cooler than at other times of the year, with less rain. Temperatures range between 24ºC—32ºC (75ºF—89ºF). The ocean is calmer at this time of year, resulting in little surf on Phuket’s white sand beaches.
April and May are the hottest months of the year, the perfect time to celebrate Songkran, the Thai New Year, with its island-wide water fight. Temperatures in these months range from 27ºC—36ºC (80ºF—95ºF).
The summer months of June through August see more frequent rains and heavier surf on the beaches. The average temperature ranges between 20ºC—33ºC (70ºF—90ºF).
The months of September and October are the rainiest months, with no blue skies for several days at times. Surf is heaviest at this time of year, with rip tide warnings at many of the west coast beaches. The East coast of Phuket has more sheltered beaches where you may still be able to swim or enjoy boating in safety.