Best Climate in Thailand: Hua Hin, Samui and Phuket

This article is general information drawn from public sources, not investment advice. For a decision about a specific property, take independent professional advice.

Two people can buy a home by the sea in Thailand in the same month and end up living in different climates. In Phuket the sky can open for days at a time between May and October. On Koh Samui May to September are among the drier months, and the island’s heavy rain arrives from October to December instead. In Hua Hin it rains on about eight days in the five months from December to April. If you are choosing where to retire, or working out when a holiday home will earn its keep, the question of where to find the best climate in Thailand deserves an answer from the record rather than from a brochure, and Thailand’s weather service has kept that record for decades.

We used the official 1991 to 2020 climate normals that the Thai Meteorological Department reports to the World Meteorological Organization, published in NOAA’s archive (WMO climate normals 1991–2020, Thailand). Each place is represented by a station in its own province: Hua Hin, Phetchaburi for Cha-Am, Koh Samui, Phuket town, Ko Lanta for Krabi, Pattaya and central Bangkok. Where we could not find a comparable official figure, we say so rather than fill the gap.

Which Thai coast gets the least rain?

Hua Hin, narrowly ahead of Cha-Am, and far ahead of the islands. At 936 mm a year it is the driest of the 25 coastal and near-coastal stations in Thailand’s 1991 to 2020 normals, with 73 days a year on which at least a millimetre of rain falls. Phuket gets nearly two and a half times as much, Koh Samui more than twice as much, and even Pattaya, which is also on the sheltered Gulf side, gets 1,106 mm.

Place (station)	Rain a year	Rainy days	Wettest months	Average humidity
Hua Hin	936 mm	73	September and October (250 mm in October)	74%
Cha-Am (Phetchaburi)	976 mm	78	September and October	76%
Pattaya	1,106 mm	82	September and October	77%
Bangkok	1,702 mm	105	May to October (336 mm in September)	73%
Koh Samui	1,994 mm	121	October to December (445 mm in November)	81%
Krabi (Ko Lanta)	2,220 mm	132	May to October	81%
Phuket (town)	2,272 mm	146	May to October (350 mm in September)	77%

The figures are thirty-year averages, so a single year can be much wetter or drier, and a downpour can still flood a street in a dry town, which our article on Hua Hin flood risk looks at coast by coast. For what each month is like to live through in Hua Hin, with temperatures and the events of the year, see our month-by-month guide to year-round living in Hua Hin.

Why is Hua Hin so dry? The rain shadow explained

From May to October the southwest monsoon carries moist air off the Andaman Sea onto Thailand’s west coast. Phuket and Krabi face it head on. The usual explanation is that Hua Hin lies on the far side of the Tenasserim range, the Tanaosri hills along the border with Myanmar, and that by the time the air has crossed them and come down to the Gulf it has lost much of its moisture. The numbers show the effect plainly: from May to August, Phuket town averages 1,035 mm of rain and Hua Hin 335 mm.

Hua Hin’s own wet spell comes at the end of the monsoon, and it is not confined to October: September brings about 130 mm and October about 250 mm, so those two months account for four-tenths of the year’s rain, with smaller amounts on eight to ten days a month from May to August. The dry half of the year is real, though: from December to April the town averages 148 mm of rain in five months, spread over about eight rainy days. It also averages about 2,220 hours of sunshine a year. We found no official sunshine figure for the island stations to compare that with, so we do not claim Hua Hin is the sunniest place on the list, only the driest.

When is the rainy season on Koh Samui?

At the opposite end of the year. Samui sits in the Gulf, and its heavy rain comes with the northeast monsoon, which picks up moisture as it crosses open water. October, November and December bring 1,003 mm between them, half the island’s annual total, with November alone averaging 445 mm. From February to September the island is comparatively dry, with between 64 mm and 134 mm a month. January is a month of transition, at about 127 mm.

That calendar is Samui’s great advantage for a holiday home. While Phuket takes about 240 to 350 mm a month from May to September, Samui takes around 100 to 135 mm, so the island’s good weather runs straight through the Andaman coast’s wet season. The end-of-year rains are heavy, though, and they are when the island floods: in December 2024 Surat Thani province declared Koh Samui a disaster area after severe flooding (Pattaya Mail), which our comparison of flood risk on Thailand’s coasts looks at in more detail. Samui is also the most humid place on our list, at 81% on average, level with Krabi, so "warm and humid" is the honest description, and it matters for maintenance as much as for comfort. Our comparison of three Koh Samui sea-view villas shows what the island offers around 20M THB.

Is Hua Hin cooler than Bangkok, Phuket or Pattaya?

Not by much, and not in the way most people expect. The average temperature across the year is almost the same all along the coast: 28.1 °C in Hua Hin, 28.0 °C on Koh Samui and in Pattaya, and 28.5 °C in Phuket town. Bangkok is the warmest at 28.9 °C, with average afternoon highs of 33.7 °C against 32.0 °C in Hua Hin, and in April its highs average 35.7 °C. The coolest afternoons on the list are in fact on Koh Samui, at 31.0 °C on average, and Pattaya’s are no hotter than Hua Hin’s. The World Bank’s 2025 climate report for Thailand names Bangkok among the places facing very high heat risk, and warns that hotter weather could shorten the peak seasons of beach destinations such as Phuket, Pattaya and Krabi (World Bank, Thailand CCDR).

Where Hua Hin stands out: humidity

Hua Hin’s average relative humidity of 74% and its average dew point of 22.8 °C are the lowest of the coastal stations we compared; Samui and Krabi sit at 81%, Phuket at 77% in town and 80% at the airport, and Pattaya at 77%. Only inland Bangkok has lower relative humidity (73%), and even there the dew point, 23.2 °C, is higher than Hua Hin’s; it is also the hottest place on the list. A lower dew point is what makes the same 32 °C afternoon feel less oppressive, and it is the measurable part of what residents describe as Hua Hin’s comfortable heat. In Hua Hin the mildest months are December and January, with average highs of about 30 °C, and the hottest are April and May, at about 33.5 °C. The dry, mild winter is also the obvious time for golf, and our guide to golf course property in Hua Hin looks at the homes beside each course.

How clean is Hua Hin’s air, and when is it hazy?

Clean from June to August, and at its worst in November and December. IQAir, which gathers readings from monitors in and around the town including one run by the Pollution Control Department, put Hua Hin’s average PM2.5 for 2019 at 21 micrograms per cubic metre, with November and December the worst months at 33.5 and 38.5, and June to August the cleanest at below 10 (IQAir, Hua Hin). The World Health Organization’s guideline, set in 2021, is 15 micrograms for a single day and 5 for the annual average (WHO global air quality guidelines), so Hua Hin’s annual figure is four times the guideline, and its air is clean for part of the year, not all of it. For Koh Samui and Phuket we found no comparable annual average from the same source, so we do not rank the islands on air quality, however fresh the sea air feels.

Fine particles, PM2.5, build up over central Thailand in the cool, dry months, when the air is still and crop residues are burned. On the morning of 24 January 2025 Bangkok’s PM2.5 reached 108 micrograms per cubic metre and more than 350 schools closed; the governor blamed crop burning, vehicle exhaust and the burning of rubbish (Al Jazeera). That was a single morning’s reading, not an average, so it cannot be set beside Hua Hin’s annual and monthly figures, and we could not confirm an annual average for Bangkok on the same basis.

What does the climate mean for owning and letting a home?

If you will live there

For someone who will live here, the case for Hua Hin is the one the data makes: the least rain of the 25 coastal stations in Thailand’s official records, the lowest humidity of the coastal stations we compared, and five months from December to April with less than 150 mm of rain between them. Add a winter in which afternoon highs average around 30 °C, and the climate case for retiring here is a strong one; our guide to retirement property in Hua Hin covers homes, costs and healthcare. From Cha-Am to Sam Roi Yot we list 119 houses and villas for sale at a median of 14.5M THB, which our guide to Hua Hin pool villas by bedroom sorts by size, and 196 condos at a median of about 8.1M THB, whose quota and transfer rules our guide to buying a condo in Hua Hin as a foreigner explains.

If you will let it

For someone who will let a property, the calendar matters more than the annual total. Samui’s drier stretch runs from February to September and takes in July and August, when Phuket is in the middle of its wet season, which is the climate argument for a villa on the island. On Koh Samui we list 48 villas and houses for sale at a median of 28M THB, from 13.5M THB for a three-bedroom sea-view villa at Sunrise Estate. Hua Hin’s driest months, December to April, line up with the European winter. Our analysis of Hua Hin rental income sets the asking rents of condos and pool villas against their asking prices in the same estates, and works out what each empty low-season month costs.

So which coast has the best climate in Thailand?

That depends on what you want from the weather, but the record answers each part of the question. For the least rain and the lowest humidity of the coastal stations we compared, it is Hua Hin. For good weather while the Andaman coast is wet, from May to September, it is Koh Samui, which pays for it with a heavy October to December. Bangkok is the hottest place on the list, while the six coastal areas all average between 28.0 °C and 28.5 °C, so on heat the coasts differ less than their reputations, and Hua Hin’s air is clean from June to August rather than all year. Climate is one reason among many to choose a coast, and it does not by itself set a property’s price or its rental return; nothing in the weather record guarantees either.

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Choose the coast, then the house

Browse what we list around Hua Hin and on Koh Samui, and tell us how you mean to use the home, to live in or to let, so we can point you to the right area and season.