When to visit Thailand, month by month.
Keyed to the circuit most operators sell: Bangkok + Phuket/Krabi. For the best all-round experience, go Jan-Feb. For the lowest prices and thinnest crowds, go Sep-Oct.
Two windows, because they answer different questions. Best experience scores the weather, the headline sights and low crowds; cheapest and quietest scores only airfare and how empty it is. Special-interest seasons (skiing, Christmas markets, aurora, festivals) are kept out of the experience score and flagged on their own line, so a niche winter draw never masquerades as the best all-round month. If you care most about one thing, read that column below.
Keyed to the Andaman coast. The Gulf islands (Samui) run the OPPOSITE cycle: their wet peak is November, exactly when Phuket comes good.
Weather and cost, month by month
| WeatherBangkok, Phuket | Costflights + hotels | |
|---|---|---|
| January | Cool dry | Peak hotels |
| February | Dry warm | Fares soften |
| March | Hot dry | Shoulder rates |
| April | Brutal heat | Songkran demand |
| May | Monsoon starts | Rates drop, fares up |
| June | Wet humid | Cheap stays, dear flights |
| July | Rainy humid | Low season |
| August | Wet monsoon | Low season |
| September | Wettest month | Cheapest overall |
| October | Rain flood | Low season value |
| November | Drying out | Rates climbing |
| December | Cool dry | Priciest month |
The Thailand attraction calendar
When each headline draw is actually at its best, or shut.
| Andaman beachesPhuket, Krabi | Gulf islandsSamui | DivingAndaman | Temples & Bangkoksightseeing | Festivalscalendar | Crowdsempty is good | |
|---|---|---|---|---|---|---|
| January | Calm clear | Drying out | Top visibility | Comfortable sightseeing | Quiet start | Busiest peak |
| February | Calm clear | Sunniest Samui | Peak visibility | Comfortable sightseeing | Chinese New Year | Still packed |
| March | Calm dry | Sunniest Samui | Peak visibility | Getting hot | Makha Bucha | Thinning out |
| April | Calm hot | Warm dry | Good, closing soon | Heat plus Songkran | Songkran newyear | Songkran spike |
| May | Rough seas | Still favourable | Parks closing | Hot wet | Visakha Bucha | Emptying out |
| June | Monsoon swell | Drier side | Parks closed | Rainy sightseeing | Few events | Low season |
| July | Wet but easing | Favourable Samui | Parks closed | Showery | Buddhist Lent | Some Euro visitors |
| August | Rough wet | Still decent | Parks closed | Frequent rain | Few events | Mild uptick |
| September | Roughest wettest | Turning wetter | Parks closed | Heavy rain | Few events | Emptiest |
| October | Wet, improving late | Wet season starts | Reopens mid-month | Flood risk | Vegetarian Festival | Still quiet |
| November | Season opening | Wettest Samui | Reopened, improving | Cool dry | Loy Krathong lanterns | Filling up |
| December | Calm clear | Drying late | Top visibility | Cool dry | New Year peak | Busiest peak |
What each month actually gives you
January is the single best all-round month for the Andaman circuit: dry, calm seas, clear skies and comfortable Bangkok sightseeing, but it is also peak season so you pay top prices and share the beaches with the biggest crowds.
February is a top-tier month for the Andaman circuit with dry weather and calm seas, and it is a slightly better value than January as air fares soften, though beaches and Bangkok stay busy.
March is a strong value shoulder month for the Andaman circuit, dry seas and clear beaches with thinning crowds, but Bangkok is turning very hot as the pre-monsoon heat builds.
April delivers calm Andaman beaches but brutal heat and the Songkran shutdown: Bangkok pushes toward 40C and 13-15 April sees water-fight street chaos with many businesses closed, so time your city days around it.
May opens the Andaman monsoon: heavy rain returns to Phuket and Bangkok, and the Similan and Surin dive parks close on 15 May, so it is a poor month for the beach-and-dive circuit even though prices start dropping.
June is deep in the Andaman monsoon with wet, humid beaches and closed Similan/Surin dive parks, and India-outbound air fares can actually spike with Indian school holidays, so it is a weak month for this circuit.
July stays wet on the Andaman coast with Similan/Surin still closed, but rain eases slightly versus May and June and prices are low, making it a budget rainy-season option for Bangkok plus resort-based Phuket rather than island-hopping.
August remains a wet, low-season month on the Andaman coast with dive parks closed, cheap and quiet but a genuine gamble on beach weather, so treat it as a value city-and-resort trip rather than an island itinerary.
September is the wettest, cheapest and emptiest month on the Andaman circuit: Phuket records its heaviest rain of the year (~325 mm) and Similan/Surin stay closed, so it is the worst month for conditions and the best for your budget.
October is a transition month: the Andaman is still wet with real Bangkok flood risk early on, but Similan/Surin reopen on 15 October and prices stay low, so the back half of the month starts to turn for the beach-and-dive circuit.
November is the sweet-spot opener for the Andaman circuit, rain drops sharply on Phuket and Bangkok turns dry and cool while the Loy Krathong and Yi Peng lantern festivals light up, though be warned this is exactly when the Gulf/Koh Samui is at its wettest.
December offers the best beach-and-dive conditions of the year on the Andaman circuit, dry, calm and clear, but it is also the most expensive and most crowded month thanks to the Christmas and New Year peak, so book early and pay up.
Worth noting
- • The Similan and Surin Islands National Parks close to ALL visitors every year from 15 May to 15 October (2026 dates confirmed). Any package selling a Similan or Surin day trip or liveaboard inside that window physically cannot run it, so treat such an offer as a red flag and ask exactly which islands you will visit.
- • Thailand's two beach coasts have OPPOSITE monsoons. The Andaman side (Phuket, Krabi, Phi Phi) is best November to April; the Gulf side (Koh Samui, Phangan, Tao) is best roughly February to September and is at its WETTEST in November. A trip that bundles Phuket and Samui will almost always catch one coast in its bad season, so confirm which coast your beach days fall on and in which month.
- • Songkran, the Thai New Year water festival (13-15 April 2026, all public holidays), is not just street fun: many shops, restaurants and offices shut for several days and transport is jammed, which can quietly wipe out planned Bangkok sightseeing if you arrive mid-festival.
- • November to February is peak EVERYTHING on the Andaman coast: best weather but the highest prices and biggest crowds, with Phuket hotel occupancy running 80-95% and luxury resorts charging 20-35% more around Christmas and New Year. December air fares from India also peak. If you want December weather without December prices, aim for late November or February-March.
- • September is Phuket's wettest month (~325 mm over 19 rainy days, TMD 1991-2020) and Bangkok's too (~335 mm), not July or August as many assume. It is also the cheapest and emptiest month, so it is a genuine budget window but a poor bet for beach and island days.
- • April looks tempting on price but is the hottest month: Bangkok averages 31.5C with warmest days near 38-40C, making outdoor temple visits gruelling, and the pre-monsoon showers are already building on the Andaman coast.
- • The visa rules for Indians changed in mid-2026. As of 17 July 2026 the 60-day visa-free scheme is still technically in force, but on 14 July 2026 the Thai cabinet approved moving India to a 30-day visa-free entitlement (a permanent status, replacing the old visa-on-arrival). It takes effect only 15 days after publication in the Royal Gazette, and that date was not yet announced, so verify your allowed stay length just before booking. The Thailand Digital Arrival Card (TDAC) is also mandatory before arrival.
- • Diving visibility on the Andaman side is best November to April; even outside the Similan/Surin closure, the May-October monsoon churns up the water, so a monsoon-season dive package will not deliver the postcard visibility shown in the brochure.
Local terms
- Songkran.
- Thai New Year in mid-April, a nationwide water-fight festival; many businesses close for a few days.
- Loy Krathong.
- Thailand’s November festival of floating candle-lit offerings, paired in the north with the Yi Peng lantern release.
- Yi Peng.
- The Chiang Mai sky-lantern festival, held with Loy Krathong in November.
- Similan.
- The Similan and Surin island dive parks off Thailand’s Andaman coast, closed to all visitors roughly mid-May to mid-October.
- monsoon.
- The rainy season. In much of Southeast Asia the coasts have opposite monsoons, so one side is wet while the other is dry.
Got a Thailand package on the table?
Check its dates against this chart, and everything else your operator did not spell out. We read the fine print so you do not have to.
Conditions verified July 2026. Confirm operator and attraction dates for the year you are travelling.