Weather in Surat Thani in May

A hard month. May is a hard month in Surat Thani, and worth planning around. You should expect rain on 26 days of the month, which is more days wet than dry.

May ranks 12 of 12 — near the bottom of Surat Thani's year. February is the month that works, and the swing between the two is 32 points, which is a different holiday rather than a slightly better one.

Rain on 26 of the month's 31 days, 8 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Natural fibres and a second shirt for the day. At 84% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 25 days top 30 °C, making the heat continuous rather than occasional. Across the twenty years measured, the hottest May day reached 38.2 °C and the coldest night fell to 23 °C, and the wettest single day dropped 64 mm — roughly 29% of the month's rain in one day.

May is one of the reliable ones — rainfall has stayed between 157 mm and 285 mm across all twenty years, a narrow enough band that the 217 mm average is something you can plan against rather than merely quote.

Wind is light at 4.8 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, high enough to notice on the warm days without dominating them.

How May sits in the year

Temperatures hold steady either side: 32.8 °C in April, 31.5 here, 30.2 in June. Nothing about the timing within the month matters much. Rain has already shifted: 10 days more than April had.

Daylight in May

Surat Thani sits close enough to the equator that daylight barely moves all year — 12.5 hours in May, against a range of just 1.1 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

An inland climate

Despite being inland, the year stays fairly even: 9.9 °C between the year's warmest afternoons and coldest nights.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

May in Surat Thani versus nearby

If Surat Thani is one option among several, the nearby comparison is worth making. Krabi is a better bet in May — within a degree on temperature, the same number of rain days. Hat Yai is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: May is a compromise. February is 32 points better and is what Surat Thani is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Surat Thani

See all twelve months in Surat Thani, or where else to go in May.