Thailand Holidays: Which Coast, Which Month and What to Sort Before You Fly

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The rules, seasons and numbers a UK trip to Thailand depends on

Each row below comes from the official source named beside it, read on 24 October 2026.

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Thailand sets and enforces its own entry rules, and they changed on 15 September 2026, when the 60-day exemption ended. On arrival, the embassy says you must show proof of accommodation and of onward travel within 30 days, and officers may also ask for proof of funds. FCDO says visa-free entry at land border checkpoints, for example coming back from Laos or Malaysia, is normally limited to 2 entries a calendar year. The TDAC is not a visa, and its official site says you do not have to print it: the QR code can be shown on your phone. Check the FCDO's Thailand entry requirements and the Royal Thai Embassy's visa page again in the week you fly.

Our guide to Thailand visa rules for UK passports covers extensions, tourist visas and stays that began before 15 September.

December to March is the driest window, except on Koh Samui

Thailand's two coasts take their rain at different times. The Tourism Authority of Thailand (TAT) says that when it is raining on the west coast, the Phuket side, it is sunny on the east coast, the Samui side, and it warns that the weather can be unpredictable. The table shows the average number of rainy days each month.

These are long-term averages from the Thai Meteorological Department, published by the World Meteorological Organization (WMO). By rainfall, the wettest month is September in Bangkok (344 mm) and Phuket (386.5 mm), August in Chiang Mai (224.6 mm) and November on Koh Samui (489.6 mm). The two coasts swap over during the year: from May to September, Koh Samui averages 14 to 16 rainy days a month against 19 to 23 in Phuket, while in November and December Phuket is the drier island.

The Andaman coast's season starts in October. TAT reports that Maya Bay on Koh Phi Phi Le reopened to visitors on 1 October 2026, and the Similan Islands reopened on 15 October after a five-month monsoon closure. Six marine national parks, including Similan, Surin, Phi Phi, Phang Nga Bay and Koh Lanta, have used electronic tickets since October 2025, so TAT advises buying yours in advance and having your passport ready.

TAT adds that October and early November can still bring rain there, and boat operators sometimes hold back when the waves run high. Build a spare day into island plans, and book ferries and island rooms early for December and January.

Songkran, Loi Krathong and the Royal Barge Procession set the festival dates

Thailand's big festivals are worth planning around, whether you want to join in or stay clear of the crowds.

• Songkran, the Thai New Year in mid-April, is a nationwide water festival recognised by UNESCO as Intangible Cultural Heritage of Humanity. For 2026, TAT listed Bangkok's main events from 9 to 15 April, with Silom and Siam Square as water zones, and advised visitors to plan travel in advance.
• Loi Krathong, the festival of lights, falls at the full moon of the 12th month of the Thai lunar calendar. For 2026, Thailand's Fine Arts Department lists Sukhothai's Loi Krathong and candle festival at Sukhothai Historical Park from 15 to 24 November. People float candlelit krathongs on rivers, lakes and canals, and TAT lists Chiang Mai's Yi Peng among the country's distinctive Loi Krathong traditions.
• The Royal Barge Procession sails on 6 November 2026, when 52 royal barges crewed by 2,200 Royal Thai Navy personnel travel the Chao Phraya River in Bangkok, past the Grand Palace, to Wat Arun for the Royal Kathin Ceremony. TAT invites visitors to watch from viewing areas on both banks of the river between Krung Thon Bridge and Wat Arun.
• Christmas and New Year in Bangkok centre on the countdowns at centralwOrld and ICONSIAM and the light shows along the Chao Phraya River, according to TAT's December guide.

Bangkok, Chiang Mai, the Andaman coast and Koh Samui suit different trips

British visitors tend to stay a while. In October 2026, TAT put the average UK stay at 14.18 days. Its list of leading UK destinations includes Bangkok, Krabi, Phuket, Surat Thani and Chiang Mai. That fits inside the 30-day visa-free stay. TAT also says Thai Airways and EVA Air run a combined 21 non-stop flights a week between Heathrow and Bangkok. British Airways, TUI and Norse Atlantic add seasonal services to Bangkok and Phuket from Gatwick and Manchester.

• Bangkok. The Grand Palace, which includes Wat Phra Kaew, sells tickets from 8:30am to 3:30pm, and its website gave the price for foreign visitors as 500 baht in October 2026. The Bureau of the Royal Household lists sleeveless shirts, shorts, mini skirts and see-through tops as unsuitable for entry, so dress for it. Its own directions suggest the orange-flag Chao Phraya Express Boat from Sathorn Pier, a short walk from BTS Saphan Taksin, to Tha Chang pier (N9). For food, TAT points to the street stalls of Yaowarat, Bangkok's Chinatown.
• Chiang Mai and the north. Chiang Mai is the cool-morning choice: its average January low is 14.2°C, against 23.9°C in Phuket, and December to February bring under 2 rainy days a month.
• Phuket, Krabi and the Andaman coast. Phuket is Thailand's largest island, and Krabi is home to Maya Bay, the Phi Phi Islands and Railay Beach among karst mountains, according to TAT. New this winter, TAT reports, Virgin Atlantic flies non-stop from Heathrow to Phuket three times a week, from 18 October 2026 to 26 March 2027. TAT's suggested 10 to 12 day route runs from Phuket Old Town to Khao Lak for the Similan Islands, sea canoeing in Phang Nga Bay, Railay, the Trang islands and Koh Lipe.
• Koh Samui and the Gulf coast. Koh Samui sits in the Gulf of Thailand, 35 km off the coast of Surat Thani, and is Thailand's second-largest island. Its best-known landmark is the Big Buddha temple, Wat Phra Yai, a 12-metre golden statue on the small island of Koh Fan, reached by a causeway. Samui's driest months are February to April.

Domestic flights, trains, ferries and scooters each have rules to know

On 19 January 2023, the State Railway of Thailand moved 52 long-distance, rapid and express services, including 14 to the north, from Hua Lamphong to Krung Thep Aphiwat Central Terminal. Krung Thep Aphiwat is near Chatuchak Weekend Market and close to the BTS Skytrain and MRT.

On domestic flights, the Civil Aviation Authority of Thailand requires the name on your boarding pass to match your passport exactly, and non-Thai passengers must show the original passport. Since 16 January 2024, a screenshot of a boarding pass is not accepted unless the airport scans boarding pass barcodes, so keep the airline's PDF, app or email pass on your phone.

Ferries and other passenger boats link the mainland and the islands. FCDO says boats can sink or collide, usually because of overloading, poor maintenance or rough seas in the monsoon.

In towns, the Grab app books cars, taxis and GrabBike rides in Thailand. FCDO advises care in open transport such as tuk-tuks, and the Grand Palace warns that a tuk-tuk can end up costing more than a taxi unless you agree the price first.

FCDO notes that the WHO ranks Thailand among the world's deadliest countries for motorcycle fatalities. To drive, you need the 1968 international driving permit and your UK licence, and the permit can only be bought in the UK. FCDO warns that hire scooters in tourist areas are often unregistered, that helmets are compulsory, and that your insurer may not cover a vehicle you would not be licensed to ride in the UK. Never hand over your passport as a deposit to a motorbike or jet-ski hire firm.

Package holidays with flights come with ATOL protection

If you book a package that includes a flight, the UK Civil Aviation Authority's ATOL scheme gives you financial protection, and you should receive an ATOL Certificate. If the travel company fails while you are away, the CAA says it will help you stay in your accommodation where possible, pay back what you spend replacing protected parts of the trip and arrange flights home, depending on the circumstances.

ATOL does not cover a flight bought with an e-ticket direct from an airline or travel company, or a hotel-only booking. It is not travel insurance either, and you cannot claim from it for cancellations, complaints, sickness or injury. Check that a company holds an ATOL before you pay.

FCDO advises against all but essential travel to the far south and the Cambodian border area

As of 24 October 2026, the Foreign, Commonwealth & Development Office (FCDO) advises against all but essential travel to Pattani, Yala and Narathiwat provinces, the Chana, Thepa, Na Thawi and Saba Yoi districts of Songkhla, and the Hat Yai to Padang Besar railway, because of regular attacks near the Malaysian border. It gives the same advice for anywhere within 20km of the land border with Cambodia. Crossings there remain suspended after fighting in July 2025 and further clashes in early December, and there are unexploded landmines in the area.

None of the main holiday areas in this guide is in those zones. FCDO warns that travelling against its advice can invalidate your travel insurance.

Elsewhere, FCDO's warnings for holidaymakers include drink spiking and methanol in alcoholic drinks, bag snatching by thieves on motorbikes, and strong riptides and jellyfish in the rainy season from May to October. It says terrorist attacks could take place anywhere in Thailand, including tourist areas, and advises avoiding protests and political gatherings.

When we read the page, FCDO also warned of severe flooding in parts of Thailand, including Bangkok, and of flight disruption from escalation in the Middle East. Check its Thailand travel advice again before you leave, and sign up for its email alerts.

TravelHealthPro lists hepatitis A and tetanus for most travellers

FCDO sends UK travellers to TravelHealthPro, run by the National Travel Health Network and Centre (NaTHNaC), and says to check vaccines and health risks at least 8 weeks before the trip. TravelHealthPro, checked in October 2026, recommends hepatitis A and tetanus for most travellers to Thailand. It lists others, including rabies, Japanese encephalitis, hepatitis B and typhoid, for some travellers depending on the trip.

It says there is a risk of dengue, spread by mosquitoes that mainly bite in the daytime. Malaria risk is low in rural, forested areas on the borders with Cambodia, Laos and Myanmar, and very low in most other areas. It lists no malaria risk in Bangkok, Chiang Mai, Chiang Rai, Koh Phangan, Koh Samui and Pattaya. The NHS says some travel vaccines are free and some you pay for, so ask your GP surgery or a travel clinic what applies to you.

FCDO adds that Bangkok and Chiang Mai can have high air pollution, including seasonal smoke haze from crop burning, which may worsen asthma. All hospitals require a guarantee of payment before treatment, and private hospitals are of a high standard but can be expensive, so check that your insurance covers local treatment and medical evacuation.

Time difference, money and the Thai laws that catch visitors out

Thailand keeps UTC+7 all year, with no daylight saving, according to the IANA time zone database. That makes it 7 hours ahead of the UK while UK clocks are on GMT, from 25 October 2026 to 28 March 2027, and 6 hours ahead during British Summer Time. Our page on the time in Chiang Mai has conversion tables for calls home.

Thailand's currency is the baht. FCDO advises using ATMs inside banks, because of skimming, and keeping your card in sight when you pay. Police may ask to see your passport, and FCDO says a copy of the photo page is usually enough, so keep one on your phone.

Some Thai laws catch visitors out. FCDO says it is illegal to possess or use any vape or e-cigarette, with no exception for tourists. Criticising the monarchy is a crime that carries a long prison sentence. Cannabis is for medical use only, with a Thai prescription, and taking it out of the country brings penalties, including fines. Drones must be registered with the NBTC within 30 days of arrival, you can bring in no more than 200 cigarettes, and alcohol sales are restricted from midnight to 11am outside licensed hotels, international airport terminals and authorised entertainment venues.

A Thailand trip runs on your phone, so set up data before the flight

Much of this trip happens on screen: the TDAC QR code, Grab rides, marine park e-tickets and the airline boarding pass that a domestic flight may not accept as a screenshot. A HelloRoam eSIM is data-only, and the plan starts when your phone first connects to a network in Thailand.

First check your phone supports eSIM, then install it at home over Wi-Fi. When you land, select the HelloRoam line for mobile data and switch Data Roaming on for it, as our guide to setting up an eSIM shows.

Your UK SIM can stay in the phone, so your British number stays with you. If you will stay on hotel and café Wi-Fi, you may not need a data plan at all.

If you would rather roam on your UK SIM, check your network's Thailand rate before you go; our guide to what data roaming costs UK travellers explains how the charges work. For a trip that continues overland to Laos or Malaysia, a HelloRoam data plan for Asia covers Thailand, Laos and Malaysia on one eSIM.