Best Time to Visit Thailand
The short answer: November to early February for the best weather, November or late October for the best value-to-weather trade. March to April is the hot, smoky stretch I avoid. May to September is the unsung sweet spot if you’re willing to deal with afternoon rain in exchange for prices that are half of high season.
Thailand has three seasons that matter for travelers:
- Cool and dry (Nov to Feb): the high season everywhere. Best weather, highest prices, fewest seats and rooms.
- Hot and dry (Mar to early May): mid 30s in Bangkok, smoky in Chiang Mai, still good on the islands.
- Hot and wet (mid-May to Oct): afternoon rains, lower prices, lush green everything.
The two coasts have slightly different rainy seasons. The Andaman side (Phuket, Krabi, Koh Lanta) gets rain from May through October. The Gulf side (Koh Samui, Koh Phangan, Koh Tao) gets rain from October through December.
Month by month
January
The best beach month of the year. Cool, dry, calm seas on both coasts. Bangkok and Chiang Mai are also at their best. High season prices everywhere.
February
Tied with January for the best month. Slightly warmer than January in the south, still cool in Chiang Mai. Chinese New Year (date varies) pushes prices up for two weeks.
March
Still dry but warmer. Chiang Mai’s air quality starts to degrade due to agricultural burning. The south is great. Bangkok is hot but manageable.
April
The hottest stretch of the year. Bangkok routinely hits 38 degrees. Chiang Mai’s smoke is at its worst, sometimes pushing into the hazardous range. Songkran (Apr 13 to 15) is the New Year water-fight festival.
The islands are mostly fine in April but the heat on the mainland is brutal.
May
The first rainy month. Usually means an hour of heavy rain late afternoon and otherwise pleasant weather. Prices drop 25 to 30 percent. Chiang Mai’s smoke clears out. Bangkok is still hot but greener.
A great month to travel if you don’t mind a daily shower.
June
Genuinely rainy on the Andaman side. Phuket and Krabi get serious afternoon storms most days. The Gulf side (Samui) is in its dry shoulder and is excellent value.
July
Similar to June. Less crowded everywhere. School holidays in some markets push prices up briefly.
August
Still rainy on the Andaman, dry on the Gulf. Bangkok and Chiang Mai are warm and overgrown. The country is half empty.
September
The wettest month on average on the Andaman side. Hotels run 40 to 50 percent off. The cleanest air of the year in Chiang Mai because the rain washes everything down.
If your trip is about pool villas, spa, and food rather than beach swimming, September is the best-value month of the year.
October
The transition month. Andaman side starts drying out by mid-month. Gulf side starts getting rain. Bangkok and Chiang Mai are pleasant. Hotel prices start climbing back toward high-season but you can still get 20 to 30 percent off if you book by late September.
Late October is my favorite weekend for a Bangkok plus Krabi long weekend. Prices are still soft, weather is mostly good.
November
The smart month. Andaman side is dry and beautiful. The Gulf has rain, sometimes serious, so avoid Samui specifically. Bangkok is just starting its dry season. Chiang Mai is cool at night, perfect during the day.
Prices are 20 to 30 percent off December. Hotels are bookable four to six weeks out. The country isn’t packed yet.
December
Peak season. Best weather of the year almost everywhere. Highest prices of the year. The riverside Bangkok hotels sell out for Christmas by September.
If you can afford it and book early, the country is at its best.
Booking timing by season
- For Christmas and New Year (Dec 20 to Jan 5): book 6 to 9 months ahead. The top hotels go first.
- For January to mid-March: book 3 to 4 months ahead.
- For shoulder (March, April, October, November): 6 to 8 weeks is usually fine.
- For low season (May to September): 2 to 4 weeks is fine. You’ll see last-minute deals.
What to do if you can only go in [bad month]
Travelers don’t always have flexibility. Here is the workaround for each tricky month:
- March or April in Chiang Mai: skip the north and add a beach instead. Or check daily AQI before each day’s activities.
- November on Koh Samui: swap to Krabi or Phuket. Andaman side is fine.
- June to October beach trip: stay on Koh Samui side rather than Phuket side. Or build the trip around a pool villa where the weather matters less.
- April heat in Bangkok: do early mornings (temples), pool afternoons, and late evenings (restaurants). Don’t try to walk the city at noon.
If you’re stuck on dates and trying to figure out the best version of your trip, email me at hello@bangkokjohn.com. I’ll usually have a recommendation.
Frequently asked questions
What is the absolute best month to visit Thailand?
December for the weather. November for the value-to-weather ratio. Late October if you're flexible and want to gamble on a great trip at half price.
December is peak weather everywhere. Bangkok is dry and cool, Chiang Mai is its best self, the islands are calm. The catch is that prices are at their highest and the top hotels book out months ahead.
November is the smart traveler's month. Weather is almost as good as December, prices are 20 to 30 percent lower, the country isn't packed, and you can still book good hotels four to six weeks out.
When should I absolutely not go?
Chiang Mai in March and April. Air quality during agricultural burning season is genuinely bad. I avoid it.
Koh Samui and the Gulf coast in November. It's their rainy peak and it can mean multi-day storms. Phuket and the Andaman side are fine in November.
Bangkok in April. It's the hottest stretch of the year and Bangkok is not at its best at 38 degrees.
Is rainy season actually a problem?
Mostly no. May through October on the Andaman side and May through September on the Gulf side usually means a heavy afternoon shower, not all-day rain. The country is greener, the crowds are gone, and prices drop 30 to 50 percent. The exception is rough seas, which can shut down boat trips for a day or two and make beach swimming less appealing. If your trip is built around the pool rather than the ocean, low season is a great value.
When is Songkran and should I go for it or avoid it?
Songkran is Thai New Year. It runs April 13 to 15 every year. The country shuts down for three days and a nationwide water fight breaks out in the streets.
If you're 18 to 35, going to Chiang Mai for Songkran is one of the best three days you'll have in Thailand. If you have kids, it's still fun but plan for the fact that you cannot stay dry. If you're trying to do quiet sightseeing, avoid those three days completely.
What about high season pricing?
Hotel prices roughly:
- High season (Dec to Feb): 100 percent (baseline) - Christmas / New Year (Dec 20 to Jan 5): 130 to 180 percent - Chinese New Year (varies): 130 to 150 percent - Shoulder (Mar, Apr, Oct, Nov): 70 to 85 percent - Low (May to Sep): 50 to 70 percent
For Christmas / New Year specifically, book 6 to 9 months ahead. Some of the riverside Bangkok hotels and the top Krabi resorts sell out by September.
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About Bangkok John
Bangkok John was started in 2020 when I posted my first hotel review. The site now publishes regularly updated guides to Bangkok, Phuket, Chiang Mai, Koh Samui, Krabi, Hua Hin, and all of Thailand.
I'm a Marriott Bonvoy Platinum Elite member and an Emirates Skywards Gold member, so I lean toward Marriott properties when the choice is close. I pay for my own rooms.
Questions? Email me at hello@bangkokjohn.com.