06Explorer

Thailand weather by month: the best time for each coast

Which coast is in season, and when?

Thailand's two coasts have opposite seasons. Pick a month and see where the sea is calm, where the rain falls and when rental demand peaks.

About 1 minute

Choose a month

The Andaman coast and the Gulf islands have opposite wet seasons. Choose a month to see where the sea is calm, where the rain falls and how busy the rental market is.

Thailand in

January

In January the sea is calm on the Andaman coast and along the eastern seaboard, and nowhere is rated wet.

Andaman coast

Phuket, Krabi, Khao Lak

Best

Andaman coast: average rainfall and daytime high in January
Weather station	Rain	High
Phuket	23 mm	32°C

Sea

Calm, clear water on the west coast. The main months for sailing, diving and island trips.

Rental demand

Peak

High season at full rates. Chinese New Year, in late January or February, adds a second surge.

Gulf islands

Koh Samui, Koh Phangan

Good

Gulf islands: average rainfall and daytime high in January
Weather station	Rain	High
Koh Samui	138 mm	29°C

Sea

The north-east monsoon is easing. Showers linger and the sea can still be choppy.

Rental demand

Peak

Busy from New Year despite lingering showers. Chinese New Year, in late January or February, adds to demand.

Eastern seaboard and upper Gulf

Pattaya, Hua Hin

Best

Eastern seaboard and upper Gulf: average rainfall and daytime high in January
Weather station	Rain	High
Pattaya	14 mm	31°C
Hua Hin	10 mm	30°C

Sea

Sheltered water, generally calm, with dry and breezy days.

Rental demand

Peak

The cool, dry months are the main season for overseas visitors and long winter stays.

The north and Bangkok

Chiang Mai, Bangkok

Best

The north and Bangkok: average rainfall and daytime high in January
Weather station	Rain	High
Chiang Mai	8 mm	29°C
Bangkok	9 mm	32°C

On the ground

Cool season. Dry, clear days, with cool nights in the north.

Rental demand

Peak

Cool season. The strongest months for visitors to Chiang Mai and for short stays in Bangkok.

The year at a glance

Each row is a zone and each cell a month. Read across to see a coast's season, and down to compare coasts in the same month.

Andaman coast

Gulf islands

Eastern seaboard and upper Gulf

The north and Bangkok

Best: under 80 mm of rain
Good: 80 to 149 mm
Mixed: 150 to 224 mm, or haze
Wet: 225 mm or more

How the ratings are set: each zone is rated on its average rainfall for the month, taken as the mean of the weather stations shown on its card. The north and Bangkok are marked mixed from February to April whatever the rainfall, because smoke haze lowers air quality in the north in those months.

Rainfall and daytime highs are long-term monthly averages recorded by the Thai Meteorological Department, and any single year can differ widely. Sea state and rental demand are our general reading of the monsoon and tourism calendars, not a forecast for any one property.

Next step

Match the coast to your calendar

If you will use the property in the European winter, the Andaman coast is in season. If you will use it in July and August, look to the Gulf islands. The months you stay away are the months a rental programme has to fill. See climate and seasons in full, the Phuket area guide and the Koh Samui area guide.

WhatsApp us Property for sale in Phuket Property for sale in Koh Samui

Where should we send it?

Climate averages: WMO World Weather Information Service, Phuket, WMO, Ko Samui, WMO, Pattaya, WMO, Hua Hin, WMO, Chiang Mai, WMO, Bangkok, Thai Meteorological Department. Bangkok figures are for 1961 to 1990.

The method

How the coast and season explorer works

Monthly rainfall and temperature are long-run climate averages.
The Andaman coast is at its best from November to April. The Gulf islands are driest from January to September, with their heaviest rain from October to December.
Rental demand follows the weather and the holiday calendar.

Rates reviewed 12 November 2026. General guidance, not legal or tax advice. Take independent legal advice before you commit to a purchase.

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Questions

Coast and season explorer: questions it answers

When is the best time to visit Phuket?

November to April, when the Andaman Sea is calm and rain is light. From May to October the south-west monsoon brings swell and frequent rain, and some west-coast beaches fly red flags.

When is the best time to visit Koh Samui?

January to September. Samui's heaviest rain falls from October to December, which is the reverse of Phuket. That makes the two coasts complementary for owners who want sun year-round.

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