Guide
School holidays are fixed and Thailand's coasts are three months out of step, so the dates pick the coast. Every UK holiday measured against both.
Almost every guide to Thailand with children is written by a family who went, and the good ones are very good. What none of them can tell you is the thing your trip actually turns on, because it needs measurement rather than memory.
You do not choose a month. A school term chooses it for you. Thailand has two coasts that run about three months out of step with each other, so for any fixed set of dates there is usually a right coast and a wrong one, and the difference between them is not marginal. In August it is the difference between a swimmable sea and red flags.
February half-term and Christmas, go to the Andaman: Phuket, Krabi, Khao Lak. Easter, May half-term and the whole of the summer holidays, cross to the Gulf: Koh Samui and its neighbours. October half-term is the one week of the year when neither coast is comfortable, and it is better spent inland than on a beach.
That is the entire decision, and the panel below is the evidence for it.
One week, usually the middle of February · measured at February
Andaman
32mm over 6 rain days
0.53m of wave
Gulf
41mm over 7 rain days
0.58m of wave
The best week of the year to be on the Andaman, and the figures are not close: it is the driest month on that coast and among the calmest.
Two weeks, late March into April · measured at April
Andaman
152mm over 20 rain days
0.47m of wave
Gulf
99mm over 13 rain days
0.30m of wave
The Andaman is turning: April rain has jumped and the crowds have not gone. The Gulf is still dry and shallow, and it is the swap most families do not know they can make.
One week, the end of May · measured at May
Andaman
269mm over 25 rain days
0.96m of wave
Gulf
113mm over 21 rain days
0.29m of wave
The southwest monsoon has arrived on the Andaman and not on the Gulf. This is the clearest single-coast answer of the year.
Six weeks, late July into August · measured at August
Andaman
248mm over 23 rain days
1.14m of wave
Gulf
90mm over 18 rain days
0.31m of wave
The one every family asks about, and the answer is the Gulf, emphatically. Do not let anyone sell you a Phuket beach holiday in August.
One week, the end of October · measured at October
Andaman
315mm over 28 rain days
0.85m of wave
Gulf
270mm over 26 rain days
0.24m of wave
The difficult one. October is the Andaman's wettest month and the Gulf's wet season is starting, so this is the week to pick the trip rather than the beach.
Two weeks, from about 18 December · measured at December
Andaman
103mm over 14 rain days
0.54m of wave
Gulf
163mm over 15 rain days
0.64m of wave
The Andaman is dry and calm and everybody knows it, so you are paying the highest prices of the year for the best conditions of it.
Rain is ERA5 reanalysis, 1995 to 2024, read at Phuket for the Andaman and Koh Samui for the Gulf. Wave height is open-meteo marine reanalysis, 2022 to 2025, read at Patong and at Chaweng. Each window is measured at the month it mostly falls in, named above, so you can check it against the same series on our month-by-month page.
Once the coast is settled, the beach still matters, and for small children it matters more than anything in the brochure. We measure wave height at each beach, so this is not a matter of opinion.
And one that the numbers alone would recommend and we will not. Mai Khao shares the calmest measured cell on the whole west coast. It also shelves steeply, pulls hard, has no lifeguards along most of its eleven kilometres, and has drowned people. It is the clearest case on this site of a figure that needs a person beside it, and a family beach list built from the wave column would put it first. All nine beaches are ranked here, with the measurements behind each.
Shallow, flagged where it matters, and on the calmer half of the coast.
The guides tend to say Thailand is easy with children, which is true and unhelpfully broad. What actually changes is specific, and it changes at four points.
The flight is the hardest part of the holiday and everything else is easier than at home. Formula, nappies and baby food are in every 7-Eleven and supermarket in a town; on a small island the choice narrows sharply, so buy on the mainland. Heat is the real constraint: plan around the middle of the day rather than through it.
This is when the beach choice above does the most work, because the difference between a shelving beach and a shore break is the difference between a holiday and a fortnight of vigilance. Minimum ages also start to bite: many boat trips will not take under-fours, and the ones that will start at seven in the morning, which is a nap problem nobody mentions until you are on the pier.
Everything opens. Snorkelling works, cooking classes generally take children from about eight, day boats stop being an endurance test, and a child of this age can walk a day in the old town without it becoming a negotiation. This is the easiest age to bring to Thailand and the one the itineraries are implicitly written for.
Diving becomes possible: PADI certifies from ten as a junior course, with depth limits, and the full qualification from fifteen. At this age the Similan trips and the longer island days stop being something you drag them through.
This is the section the family blogs mostly leave out, and the one search engines fill with advertising. What follows is what the UK’s National Travel Health Network and Centre publishes for Thailand. It is a summary rather than advice: the source is TravelHealthPro’s Thailand page and a travel clinic is the place to make decisions.
The practical version for a beach fortnight: the mosquito risk is higher in the city than on the coast, repellent matters most at dawn and dusk, and the animal you should teach a child to walk away from is a monkey rather than a snake.
Thailand requires children under six to be in a car seat. It is Section 123 of the Land Traffic Act, it became operative on 17 August 2023, and the fine reaches 2,000 baht.
The part that matters to you is what it excludes. The requirement applies to private cars, pickups and minivans. It does not extend to public vehicles, which includes the airport transfer van most families are actually sitting in, and standard taxis and Grab cars do not carry seats. So there is a law, it is inconsistently enforced, and it does not cover the journey you are most likely to make with a tired toddler at midnight.
If that matters to you, arrange a seat with the hotel transfer in advance or bring one. It is not a thing you can solve at the arrivals rank.
Britain to Bangkok is eleven to twelve hours nonstop, and Phuket now has its own: Virgin Atlantic’s Heathrow service began on 18 October 2026, runs three times a week, and is winter-only, which is worth knowing because it exists precisely in the months the Andaman is dry. Our flights page has the detail.
Inside Thailand, domestic flights cover the long hops for about the price of a family dinner and save a day each way. Between the beaches on Phuket there is one bus route, the Smart Bus down the west coast, and a family with luggage and small children will still want a car or a transfer for the airport run, and it is why our where-to-stay guide argues so hard for picking a base you can walk from.
Thai attitudes to children are genuinely warm and staff will pick your baby up without asking, which delights some parents and startles others. Highchairs are common in tourist areas and rare outside them. Pharmacies are everywhere, well stocked and staffed by people who speak enough English. Private hospitals in Phuket, Bangkok and Samui are of a standard that surprises visitors, and they will want payment or insurance confirmation up front, so carry the policy number rather than the paperwork.
Food is the concern parents raise most and the one that resolves fastest. Plain rice, grilled chicken, omelettes, noodles without chilli and fresh fruit are available on every street, and “mai phet” is the only Thai most families need. The heat is the harder adjustment, and the answer is the same everywhere: mornings and late afternoons outside, the middle of the day indoors or in the water.
Two nights in Bangkok at the start, because the flight lands there and a child who has crossed six time zones should not be put straight on a connection. Then one coast, chosen by the panel above, for nine or ten nights in one place rather than three. Then a night back near the airport before flying.
The mistake families make is moving. Thailand rewards staying put with children far more than it rewards a circuit, and every internal move costs the better part of a day at both ends. If two weeks feels like it should hold three destinations, our two-week itineraries set out what each move actually costs.
Very. Thai attitudes to children are unusually warm, restaurants and hotels accommodate them without fuss, and the practical infrastructure is good. The one thing that genuinely decides whether the trip works is the month, because the two coasts keep opposite seasons and school holidays are not moveable.
It depends on when you can travel. In February or December the Andaman coast, and Krabi in particular, has the calmest swimming water of the beaches we measure. In the summer holidays the Gulf islands are the answer, because the Andaman is in its monsoon and the Gulf is not.
In the right season and on the right coast, yes. The Krabi bays never average more than about 0.4 metres of wave height in any month of the year, because they sit inside Phang Nga bay with Phuket island in the way. Phuket's own west coast reaches over 1.3 metres in July, and its red flags mean rip currents.
Eleven and a half to twelve hours nonstop from London Heathrow, or about fourteen with one stop from anywhere else in Britain. The overnight direction going out and the daytime one coming back suits most families better than the reverse.
Repellent morning and evening, and long sleeves at dusk. Food is rarely the problem people expect: rice, noodles, grilled chicken, omelettes, fruit and mild dishes are everywhere, and mai phet means not spicy.