The essentials
When to go to Thailand, in brief
November to March: the sweet spot
Cool, dry season. Clear skies from North to South, 28-32°C, low humidity. It is also the busiest stretch.
Andaman vs Gulf
The Andaman (Phuket, Krabi) is dry from November to April. The Gulf (Koh Samui) shifts: drier February to August, wet October to December.
April: hot and festive
Up to 36°C, the heat peak. But it is also Songkran, the Thai New Year and its nationwide water fight, 13 to 15.
May to October: the monsoon
Mostly late-day showers until August, then heavy rain in September-October. The trade-off is low prices and green landscapes.
September-October: avoid for the beach
Monsoon peak on the Andaman, choppy sea, some islands slow down. The North and culture stay doable.
Two festivals to plan around
Songkran in April (nationwide water fight) and Loy Krathong in November (lanterns). Two highlights worth timing your trip for.
The verdict
The best periods
Nov - March
Dry and cool everywhere. The prime window to combine Bangkok, the North and the southern beaches. Book 2 to 3 months ahead.
April - August
April is scorching (Songkran). From May to August, short showers but soft prices and few crowds.
Sept - Oct
Monsoon peak, mostly on the Andaman. Long rains, choppy sea, a few boat services reduced.
Month by month
The full calendar
Tap a month for the detailed guide: weather by region, where to go, festivals.
28-32°C
Dry, peak season
29-33°C
Dry, gentle heat
30-34°C
Heat rising
32-36°C
Very hot, Songkran
30-34°C
First rains
29-33°C
Variable showers
29-33°C
Late-day rain
29-33°C
Rainy spells
28-32°C
Monsoon peak
28-32°C
Wet Andaman
28-32°C
Dry returns
27-31°C
Dry, cool, high season
Climate
Climate by region
| Region | Dry season | Wet season | Verdict |
|---|---|---|---|
| Bangkok & Central | Nov-Feb: 28-32°C, dry | May-Oct: hot and humid | Ideal Nov-Feb |
| North (Chiang Mai) | Nov-Feb: cool, 15-30°C | Mar-Apr: burning (haze); May-Oct: rain | Ideal Nov-Feb |
| Andaman (Phuket, Krabi) | Nov-Apr: dry, flat sea | May-Oct: monsoon, peak Sept-Oct | Ideal Nov-April |
| Gulf (Koh Samui) | Feb-Aug: the driest | Oct-Dec: wet season, choppy sea | Ideal Feb-Aug |
Calendar
The key events of the year
Songkran (Thai New Year)
The country's biggest festival: a nationwide water fight in the streets, from the South to Chiang Mai. Festive but very hot.
🇹🇭 Nationwide
Loy Krathong & Yi Peng
Floating and sky lantern releases. The sight is most striking in Chiang Mai and Sukhothai.
🇹🇭 Chiang Mai, Sukhothai
Phuket Vegetarian Festival
Nine days of Chinese-Thai rituals, processions and meat-free food stalls.
🇹🇭 Phuket
New Year
Countdown and fireworks over the Chao Phraya in Bangkok, in the heart of the dry season.
🇹🇭 Bangkok
Our analysis
Thailand follows one simple rule: aim for the dry season, November to March. The whole country plays the same tune then, from the cool North to the southern beaches. The rest of the year calls for a trade-off, and that is where a trip is made or broken.
The dry season, November to March
This is the prime window. The northeast trade winds sweep the humidity away, skies clear and temperatures stay manageable: 28 to 32°C by day, cooler nights. December and January are the most pleasant months, and so the busiest. Prices climb around Christmas and New Year, when you should book two to three months ahead.
February and March extend the dry season, with heat building gently. It is still an excellent time to combine Bangkok, the North and a southern island without facing the monsoon.
April: the heat and Songkran
April stands apart. It is the hottest month, up to 36°C, but also Songkran, when the country turns into a three-day water fight. You go for the party, not for lazing on the sand.
The late-season trap
From May, the monsoon arrives from the southwest. Until August, showers stay short, fall mostly late in the day, and prices drop: a fair compromise if you can handle a changing sky. September and October, by contrast, bring the heaviest rain to the Andaman.
One nuance few travelers anticipate: the Gulf of Thailand runs on its own calendar and stays drier when the Andaman floods. Koh Samui and Koh Phangan often save a late-season trip, as long as you avoid October to December, their wettest stretch.
FAQ
Frequently asked questions
When is the best time to visit Thailand? +
From November to March: a cool, dry season, 28-32°C, low humidity and a calm sea on the Andaman coast. It is the prime window, and the busiest.
What is the worst time to visit Thailand? +
September and October are the monsoon peak, especially on the Andaman coast: long rains and a choppy sea. For the beach, this is the time to avoid.
Can you visit Thailand during the rainy season? +
Yes. From May to August, showers are often short and fall late in the day. Prices are low, landscapes green and sites less crowded.
When to visit the islands, Andaman or Gulf? +
The Andaman (Phuket, Krabi, Koh Lanta) is at its best from November to April. The Gulf (Koh Samui, Koh Phangan) shifts: drier February to August, and wet from October to December.
When is Songkran in 2026? +
From 13 to 15 April. It is the Thai New Year and its nationwide water fight. Expect the hottest weather of the year, up to 36°C.
Do you need to book far ahead? +
For high season (December to February), yes: book flights and hotels two to three months ahead, especially around Christmas and New Year.
Marie Laurent · Southeast Asia specialist
Updated May 31, 2026