Weather in Phuket in May

How May compares

May is the 4th warmest month of the year in Phuket and ranks 25th of 134 destinations we compare for May - see where else is hot in May. Within Thailand it is 6th of 6 (Thailand in May). Against London's average high of 16.6°C in May, Phuket is 12.5°C warmer by day and 18.2°C warmer at night.

Daytime and night-time in May

The typical May day in Phuket peaks at 29.1°C, but that is an average: the warmest 10% of days reach 30.6°C or more. About 100% of days top 25°C and 1 in 5 pass 30°C. Nights average 26.5°C; one night in ten drops to 25.4°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest May day here reached 34.1°C (2019-05-02) and the coldest night 24.0°C (2017-05-11).

Rain in May

Wet (more than 8 rainy days): about 25 days with 1 mm or more, 257 mm in total. Year to year it varies a lot - the wettest May was 1994 with 451 mm, the driest 2010 with 119 mm. Humidity averages 82%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in May

The sea averages 30.2°C - warm enough to swim (22°c+). Depending on the year it ranges from 29.4°C to 30.7°C. For the warmest sea here, come in April (30.2°C).

Sunshine and daylight

Around 2.0 hours of sunshine a day (estimated from cloud cover), 12.4 hours of daylight: the sun rises about 06:08 and sets about 18:37 local time in mid-May. Average cloud cover is 84%.

Is May a good time to visit Phuket?

It is a reasonable choice: hot days but expect showers. The best months for Phuket on our scoring are February, January, March; months averaging 25°C or more: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec.

Hot days, with little cooling after dark

The heat is dependable in May; comfortable cooling is less so. Average night-time lows of 26.5°C mean evenings stay warm, while 82% humidity can make the daytime heat feel more demanding. Choose light, loose clothing and accommodation with air conditioning if warm nights affect your sleep. Keep strenuous outdoor plans flexible and leave room for breaks around midday. Temperatures reach 30°C on 22% of days, so it is not usually extreme heat that defines the month, but the combination of warmth and moisture. This suits travellers happy to slow their pace, rather than anyone hoping for fresh evenings after a hot afternoon.

A warm sea, but a weather-dependent beach holiday

The sea is warm enough for swimming, though at 30.2°C it is unlikely to feel particularly cooling. The bigger catch for a beach-focused trip is the sky: May averages about 2.0 hours of sunshine a day despite 12.4 hours of daylight. With about 25 rainy days, wet weather needs to be part of your plans rather than treated as an unlikely interruption. That does not mean every rainy day is a complete washout, but you should not build the holiday around long sunny stretches. Pack a lightweight waterproof and something to protect your belongings from rain. Water temperature alone cannot tell you if swimming conditions are safe, so follow local advice on the day.