Koh Samui has something that sets it apart from other Thai islands: its calendar. While much of the country gets wet between May and October, the UK FCDO advice (consulted in November 2026) says Koh Samui and south-east Thailand have their rainy season from November to March. It is the fact that changes a trip most and the first thing to check if you plan to combine this island with Phuket or the north.
What kind of island it is
Samui, in the Gulf of Thailand, offers beaches with greenery down to the water, rocky coves with turquoise water and a green interior that invites you to rent a car or hire a driver. Off its coast lies Ang Thong National Marine Park, an archipelago of jungle-covered islands visited on a day trip and among the most photogenic landscapes in the area. For a couple, the winning formula is usually a quiet place to stay, a couple of excursions and plenty of unplanned time.
Boats and transfers
Reaching the islands almost always means water. The FCDO warns that boats between the mainland and islands can sink or collide, often through overloading, poor maintenance or rough seas. Choose serious operators, do not board a visibly overloaded vessel and check that life jackets are on board. On bad-sea days, stay ashore: the excursion can be repeated, the scare cannot.
Motorbikes, passports and insurance
Renting a scooter is tempting on an island with coastal roads, but advisories remind you that Thailand is among the countries with the most motorcycle deaths, that helmets are mandatory, that many hire bikes in tourist areas are unregistered and that riding without a valid licence can void your insurance. The 1968 international permit is required as well as your licence. Do not hand your passport over as security to bike or jet-ski businesses: they may keep it against claimed damage.
Sea and currents
The advice mentions jellyfish near the shore from May to October and strong rip currents that have caused drownings, especially in monsoon season. Respect the flags and ask where you are staying about the day's conditions.
Laws worth knowing
Vaping is banned for everyone; smoking in public can cost up to 5,000 baht; recreational cannabis is illegal; and sharing photos of people drinking alcohol or wearing clothing considered inappropriate can be an offence for the uploader and those pictured. We explain it in our guide to Thai laws. The FCDO also reminds you that carrying more than 120 playing cards is illegal (Playing Cards Act 1943) and that drones must be registered with the NBTC.
Drinks and nightlife
Drink spiking and drug-assisted assaults have been described in tourist areas, with victims of both sexes, mostly at large events and near bars late at night. Keep your drink in sight, do not accept drinks from strangers, arrange your return and avoid unlicensed vehicles. Alcohol sales are restricted between midnight and 11:00, and methanol in counterfeit drinks has caused deaths.
What we do not publish
We include no lifestyle venues on Koh Samui because we could not verify any with a live official website and a checkable policy. We would rather give you an honest guide than a dubious list. Nor do we give space to anything suggesting sex tourism.
Health and logistics
Take out insurance with medical and evacuation cover: hospitals require a payment guarantee before treatment and, outside Bangkok, public ones may fall short of UK standards. Check vaccinations eight weeks ahead and keep dengue and rabies in mind.
A couple's plan, step by step
So that Koh Samui does not become a string of improvised decisions, we suggest a simple method. First, sit down together with your own country's official advice and this page, and note three things: what you want to experience, what worries you and what limits each of you has. Second, divide your time: beach days, an Ang Thong trip if the sea allows and unscheduled time. Third, agree before going out on a signal for changing plans without explanations, and a meeting point in case you get separated. Fourth, save your embassy's phone number, the emergency number and your accommodation's address on your phone and on paper. Fifth, check your insurance: it should cover medical care, evacuation and the activities you plan to do.
At BarSwinger we believe travelling as a couple is, above all, communication and consent: deciding together, stopping when either of you asks and not doing anything just because "that is how it is done here". That attitude is worth more than any guide and is what turns Koh Samui into a lovely memory instead of an anecdote with a bad ending.
Before you book: three checks
The first is the date: compare the weather and the official advisories in the weeks before, because conditions change. The second is accommodation: choose one with an official website, a clear policy and recent reviews from sources you can verify. The third is the contingency budget: set aside an amount for an extra transfer, a medical consultation or a flight change. If any of the three fails, it is better to adjust the plan than to improvise on the way. If anything on this page has changed by the time you travel, trust the latest official information and, if you write to us, we will correct it.
Frequently asked questions
When does it rain on Koh Samui? According to official advice, from November to March in the Koh Samui and south-east area.
Is Ang Thong worth it? It is a marine park of jungle islands, visited on a trip from the island and one of the most photogenic landscapes around.
What if I lose my passport? Contact your embassy or consulate and report it to the police; carry a copy of the photo page in case you are asked for it.
