Weather in Thailand by Month: Is It a Good Time to Go? (Andaman, Gulf and North)

Thailand has two coasts on opposite weather calendars, so “is it a good time to go?” depends on where you are heading. Use this guide to the weather in Thailand by month to pick the right region for your dates.

The short answer

• Best overall: November to February for Bangkok, the north and the Andaman coast (Phuket, Krabi).
• Beaches on the Gulf (Koh Samui, Koh Phangan, Koh Tao): roughly January to August.
• Lower prices and fewer crowds: May to early September, with the Gulf for beaches.

Thailand weather by month

January

Dry almost everywhere and a strong all-round month. Peak prices and crowds. Both coasts are usable. Is January a good time to visit Thailand? Yes, book early.

February

Still dry and warm, and the north is clear before the smoke season. A good alternative to January with slightly fewer crowds. Is February a good time to go? Yes, for beaches, Bangkok and the north.

March

Hotter and drier. Bangkok and the north get very warm, and haze starts to build around Chiang Mai. Beaches are still good on both coasts. Daytime temperatures commonly reach the mid-30s°C (mid-90s°F).

April

The hottest month, with temperatures in Bangkok and the north reaching around 38 to 40°C. Burning season smoke in the north. Songkran, the water festival, takes place in mid-April. Choose beaches or plan indoor and water activities.

May

The monsoon begins on the Andaman coast and the first rains break the heat in Bangkok. The Gulf islands stay mostly dry. A turning point and often good value.

June, July and August

Green season. Expect a heavy shower on many afternoons, then clear spells. The Gulf (Koh Samui) is the better beach choice; the Andaman has rougher seas. Is July a good time to visit Thailand? Yes, for the Gulf, culture and lower prices.

September

Among the wettest months overall. Head to the Gulf rather than the Andaman, or keep plans flexible.

October

A transition. The Andaman coast starts to clear while the Gulf turns wetter.

November

The Gulf’s wettest month, while the north and Andaman improve. A good time for Bangkok, Chiang Mai and Phuket.

December

Cool and dry, and very busy. Peak season in most regions, with Christmas and New Year demand. Andaman is the safer beach choice; the Gulf may still be wet early in the month. Thailand travel in December: book flights and hotels well ahead.

Typical temperatures at a glance

These are typical daytime ranges, not forecasts. Humidity makes most of them feel warmer.

Region	Nov–Feb	Mar–May	Jun–Oct
Bangkok and central plains	Warm, around 30–32°C, less humid	Very hot, often 35°C or more	Hot and humid, with heavy showers
Chiang Mai and the north	Pleasant days, cool nights (can drop to the mid-teens °C)	Hot, with haze from crop burning	Green, warm and wet
Phuket and Krabi (Andaman)	Sunny, calm sea, around 31–33°C	Hot, still mostly dry until May	Monsoon: rough seas, frequent rain
Koh Samui (Gulf)	Wettest in Nov, clearing in Jan	Dry and hot, calm sea	Mostly dry with some showers until Oct

Two coasts, two calendars

• Andaman (Phuket, Krabi, Khao Lak): dry and calm roughly November to April; heavy rain and rough seas about May to October.
• Gulf (Koh Samui, Koh Phangan, Koh Tao): driest roughly January to August; heaviest rain October to December.
• North (Chiang Mai, Chiang Rai): best November to early February; haze and burning season from roughly February to April.

See how the two islands compare in Koh Samui vs Phuket, and our best time to visit Thailand page.

Festivals by month

• January or February: Chinese New Year, celebrated in Bangkok’s Chinatown (Yaowarat) and in Phuket Town.
• April 13 to 15: Songkran, the Thai New Year water festival. It is fun, but transport and hotels are busy and you will get wet.
• September or October: the Phuket Vegetarian Festival, a striking Taoist festival with processions in Phuket Town.
• October or November: the end of Buddhist Lent, with ceremonies at temples across the country.
• November: Loy Krathong, with candlelit floats on rivers and lakes nationwide, and the Yi Peng lantern festival in Chiang Mai.

Traveling in the green season

From May to October, the rain usually comes in heavy bursts, often in the afternoon or overnight, rather than all day. Many days still have long sunny spells. Hotel rates fall, especially on the Andaman coast, and the north turns lush. A few practical points help:

• Plan temples, markets and outdoor sightseeing in the morning.
• On the Andaman side, choose a beach with a sheltered bay, and accept that some island boat trips will be cancelled when the sea is rough. Swim only where it is safe: red flags mean strong currents.
• Some marine national parks, including the Similan Islands, close for several months during the monsoon.
• Keep a buffer day before international flights if your route depends on boats.

What to pack by season

Light, breathable clothing works all year, plus a layer that covers shoulders and knees for temples. From December to February, add a fleece or light jacket for the mountains of the north, where early mornings are cool. In the rainy months, bring a compact umbrella and quick-drying shoes. From February to April, travelers with breathing problems should check air-quality forecasts for the north before booking.

Plan your Thailand trip

Match the route to your month with our Thailand tour packages guide and private Thailand tours.

Thailand weather by month: FAQ

What is the best month to visit Thailand?

January and February are the most reliable for most regions.

Is Thailand hot in March?

Yes, March is hot and dry, and haze starts in the north.

Is December a good time to go to Thailand?

Yes, but it is peak season; choose the Andaman side for beaches.

Is August a bad time to visit?

Not for the Gulf islands; Andaman beaches are rougher.

Which month is wettest?

September overall, and November on Koh Samui.

When is the Songkran festival?

Songkran is celebrated from April 13 to 15 each year, with water fights in most cities and the biggest celebrations in Bangkok and Chiang Mai.

Can I visit Thailand in the rainy season?

Yes. Showers are usually short and heavy, prices are lower, and the Gulf islands are often dry from June to August.