Best Time to Visit Thailand: Month-by-Month Guide by Coast for 2026
Best time to visit Thailand: November to February for most trips, but the Andaman coast, Gulf islands and north each run on a different calendar.
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In this guide
The best time to visit Thailand is November to February, when the country is at its coolest, driest and sunniest. It is also the most expensive and crowded stretch of the year. It is not the right answer for every coast. The Andaman side (Phuket, Krabi) and the Gulf islands (Koh Samui, Koh Phangan) run on different rain calendars. The north has a smoke season that most date advice ignores.
So the useful question is “which month for which place”.
At a glance:
- Overall: November to February, January safest.
- Andaman coast: November to March.
- Gulf islands: December to April, plus a dry July and August.
- North: November to January, before the smoke.
- Cheapest: June to October, but not on the Andaman side.
When is the best time to visit Thailand overall?
November to February, with January the safest single month. Bangkok gets about 8mm of rain in January and 21mm in February, against 241mm in September (WeatherSpark’s 1991-2020 data). Rough Guides gives the same window for the north and the central plains, and puts the Andaman coast at November to March.
The cool season is a relative term. Bangkok’s average high drops to roughly 31C in December, which is still warm. You get lower humidity and clear skies, not a chill. Only the northern hills feel properly cool at night.
The catch is price and crowds. Hotels and flights sell out early in these months, and December is the busiest because of the holiday weeks. Chiang Mai’s Loi Krathong and Yi Peng festivals fall on 24 to 25 November in 2026, and the dates for those and for Songkran in April are laid out in our guide to Thailand holidays and festivals.
Thailand’s three seasons in short:
- Cool and dry: November to February
- Hot: March to May, with April the peak
- Rainy: June to October, starting in mid-May in 2026
Which coast should you pick, and when?
The Andaman coast is best from November to March, the Gulf islands from December to April, and the north from November to January. Choosing by coast saves more of a trip than choosing by month.
Andaman coast: Phuket, Krabi, the Similans
The southwest monsoon hits this coast from May to October. Wego’s regional breakdown has Phuket’s rainfall peaking near 318mm in September, with waves of 2 to 3 metres and ferries often cancelled or delayed from June to September. From November the sea calms and visibility improves. Our Phuket travel guide and Krabi travel guide cover where to base yourself in those months. Book the island-hopping boat tours for the middle of the dry season, when cancellations are rarest.
A white-sand bay in the Similan Islands, off the Andaman coast, in clear conditions.
Gulf islands: Koh Samui, Koh Phangan, Koh Tao
This coast flips the calendar. Wego puts Koh Samui’s wettest month at November, with about 445mm, and October near 295mm. From January to September it stays under 140mm a month. Thailand Magazine describes July as the driest, clearest window of the year there, with a short shower most days, usually in the late afternoon.
Sources disagree on December. Rough Guides counts December to April as the good Gulf season, while Wego lists October to December as the northeast monsoon period. Treat early December as a gamble and January onward as safe.
That makes July and August the reverse of the usual advice. If your only free weeks are in the northern summer, Samui is a better beach bet than Phuket, even though mainland Thailand is in its green season.
Calm water and wooded headlands off Koh Samui’s east coast at dusk.
The north: Chiang Mai and Chiang Rai
November to February is clear and comfortable. Then comes the burning season. Fire activity picks up in February and peaks in March as farmers clear fields, and Khaosod English reported that around 1 April 2026 Chiang Mai ranked as the world’s most polluted major city for a fourth consecutive day, with PM2.5 readings of 80 to 293 micrograms per cubic metre. About 70% of the fine particles in April come from burning biomass. Thunderstorms cleared the air in late April.
So if hiking or viewpoints are the point of your trip, aim for November to January. The Chiang Mai travel guide has the city plan, and the green season suits slow village visits instead.
Young rice on terraces near Mae Klang Luang, Doi Inthanon National Park, bright green in the rainy season.
Bangkok and the central plains
Bangkok is hot all year. The average high is about 34.6C in April and about 31C in December. Rain builds from 68mm in April to 182mm in May and 207mm in August, before September’s 241mm. The best sightseeing weather is November to February, but the city works year-round because so much is indoors, from malls to the Grand Palace route. A day trip to Ayutthaya is the one outing worth moving to a cool-season morning.
The overlap most guides skip. Only one stretch suits every region at once. January and the first half of February. The north is clear before the smoke builds, Bangkok is at its driest, the Andaman coast is calm, and the Gulf islands are in their dry window. If you want Bangkok, the north and an island on one trip, build it there. Outside it, you give something up, usually the north’s air or one coast’s sea.
A shoulder season is the short gap between peak and low prices, and it is where value hides. In Thailand it is narrow and differs by coast, so the safest approach is to pick your region first and check the Thai Meteorological Department’s monthly reports before you commit to anything non-refundable.
Two dates also move prices regardless of weather: Songkran in mid-April and the Christmas to New Year weeks. Price those first, then work backwards to a month.
Booking order matters more than people think. Fix flights and the Andaman or Gulf hotel first, because the dry-season beach rooms go earliest. Leave the Bangkok nights flexible, since the capital has beds in every month. And keep one spare day before any international flight home if you cross to the islands by ferry, because rough sea days can strand you.
Find experiences for your Thailand trip
If you book through these links, we may earn a commission at no extra cost to you.Is the rainy season really that bad?
Not on the Gulf side, and not everywhere else either. Wego describes typical monsoon rain as an intense burst of an hour or two, often in the afternoon, instead of an all-day soak. You can plan around that: temples and markets in the morning, a long lunch while it passes.
The upside is price. Wego notes that hotels in places like Phuket cut rates by as much as 50% in low season while occupancy only drops by about a third. The downside is concentrated on the Andaman sea, where rough water cancels boats and makes some beaches unswimmable.
A practical rule: in the wet months, keep the Andaman coast out of a tight schedule. If you are reading this in October 2026 with a trip in the next few months, remember that the Gulf islands are about to get their heaviest rain of the year in November, so Samui is a poor pick for that month.
Which month should you choose?
| Month | North | Bangkok | Andaman coast | Gulf islands | Crowds and prices |
|---|---|---|---|---|---|
| January | Best | Best (8mm rain) | Best | Good | Peak |
| February | Good, smoke starts | Best (21mm) | Best | Best | Peak |
| March | Smokiest | Hot, dry (31mm) | Good | Best | High |
| April | Smoky, hot | Hottest (34.6C) | Hot, rain begins | Best | High, Songkran spike |
| May | Rain clears smoke | Wet (182mm) | Monsoon begins | Good | Falling |
| June | Green season | Wet (159mm) | Rough seas | Good | Low |
| July | Green season | Wet (167mm) | Rough seas | Driest window | Low to medium |
| August | Green season | Wet (207mm) | Rough seas | Good | Low to medium |
| September | Wettest | Wettest (241mm) | Wettest (about 318mm in Phuket) | Good | Lowest |
| October | Wet, drying | Wet | Wet, easing | Wet (about 295mm in Samui) | Low |
| November | Best | Good | Calm returns | Wettest (about 445mm in Samui) | Rising, Loi Krathong |
| December | Best | Best (9mm) | Best | Mixed, improving | Peak, holiday weeks |
Bangkok rainfall figures are WeatherSpark averages; Phuket and Samui rainfall is from Wego. The remaining ratings summarise the Rough Guides regional guidance.
If your priorities are clear, the choice is short:
- Beaches and diving on the Andaman side: December to March.
- Beaches with a school-holiday budget: Koh Samui in July and August.
- Temples, trekking and food in the north: November to January.
- Lowest prices and you can take showers: June to October, away from the Andaman coast.
For a route that fits the cool season, see our two-week Thailand itinerary or the shorter seven-day plan. What each season costs is in the Thailand trip cost breakdown. Browse every Thailand tip and planning article when your dates are set.
Know before you go
Thailand at a glance
Best time to visit
November to February
- January: hot, mostly dry
- February: hot, some showers
- March: hot, some showers
- April: hot, some showers
- May: hot, rainy
- June: hot, rainy
- July: hot, very wet
- August: hot, very wet
- September: hot, very wet
- October: hot, very wet
- November: hot, some showers
- December: hot, mostly dry
Mostly dry Some showers Rainy Very wet
- Capital
- Bangkok
- Currency
- Thai baht (THB)
- Language
- Thai
- Time zone
- ICT, UTC+7
- Plugs
- Type A / B / C / O, 230 V
- Driving
- On the left
Emergency191 police, 1155 tourist police
Frequently asked questions
What is the best month to visit Thailand?
January. It sits inside the November to February cool season, Bangkok gets only about 8mm of rain, and both the Andaman coast and the north are in good shape. December is almost as good but busier. If you can only travel in another month, choose the coast by season instead of accepting a wet beach.
What is the rainy season in Thailand?
It depends on the coast. Nationally the rainy season runs from about June to October, and in 2026 the Thai Meteorological Department declared it under way from 15 May. The Andaman coast is wet from May to October, while the Gulf islands such as Koh Samui get their heaviest rain from October to December, peaking in November.
Is it worth visiting Thailand in the rainy season?
Yes, if you pick the right coast. Rain usually comes as a heavy burst of an hour or two, often in the afternoon, rather than all day. Hotels in places like Phuket can discount by as much as 50%. The catch is rough seas on the Andaman side, where ferries are often cancelled or delayed from June to September.
When is the smoky season in Chiang Mai?
February to April, with fires peaking in March. In early April 2026 Chiang Mai ranked as the most polluted major city in the world for several days running, with PM2.5 readings between 80 and 293 micrograms per cubic metre. Air improved in late April once thunderstorms arrived. If you have asthma or want clear mountain views, go to the north between November and January.
Which Thai islands are good in July and August?
Koh Samui, Koh Phangan and Koh Tao on the Gulf side. Samui stays under 140mm of rain a month from January to September, and its rain tends to be short afternoon showers. The Andaman coast, including Phuket and Krabi, is at its roughest in the same months.
Which is hotter, Bangkok in March or in April?
April. Bangkok averages a high of about 34.6C in April, the hottest month of the year, and about 31C in December. The city is hot in every month, so rain and humidity, not temperature, decide when it is pleasant.
Useful links (6)
- Best time to visit Thailand, Rough Guides— roughguides.com
- Thailand Monsoon Season 2026: When It Rains and Where to Go, Wego— blog.wego.com
- Average weather in Bangkok, WeatherSpark (ERA5, 1991-2020)— weatherspark.com
- Chiang Mai air quality improves as hotspots decline, Khaosod English (30 April 2026)— khaosodenglish.com
- Weather and climate in Thailand in July, Thailand Magazine— thailandmagazine.com
- Thai Meteorological Department climate reports— tmd.go.th
Photo credits
Thank you to Mathias Krumbholz, Lakshmi Sawitri, Damian Moore and Voranat Rajchatan for sharing these beautiful photographs and helping bring this guide to life.
Editorial byline
Sophie Bennett Asia editor
Sophie covers Japan and Thailand for Epic Trip Ideas: temple towns, festivals, rail journeys, street food and island routes, planned around seasons and local holidays. Sophie Bennett is a pen name the Epic Trip Ideas editors use for Japan and Thailand; every guide is checked against official sources before it goes live.
