Phuket Weather

The annual monsoon begins earlier (May) than in northern Thailand but generally ends late in October. Other than the period from 15 September to 15 October, when the rain falls steadily, most monsoon days are rain-free except for showers in the afternoon.

The best months are November through February when daytime and nighttime temperatures are low. In the hot season, afternoon temperatures can rise to 30-34 degrees C (86-93 degrees F) but are tempered by cool breezes and dip to tolerable levels at night. Temperatures range from a daytime high of 34 degrees C (93 degrees F) in the hot season to a nighttime low of 21 degrees C (70 degrees F) in the cool season. The water temperature never drops below 20 degrees C (68 degrees F).

Hot season
March to mid-May
24-34 degrees C (80-93 degrees F)

Rainy season
Mid-May to mid-November
23-32 degrees C (74-91 degrees F)

Cool season
November to February
21-33 degrees C (70-90 degrees F)

So the best time for a visit here would be during the cool season, but if you don't mind some rain (short showers during the day) and have in mind that it might be unsafe to swim (red flag on the beach), you can easily enjoy this island all year around.