Thailand is not one climate in a backpack. Cool-season Chiang Mai at night is not a Similan longtail, which is not a Bangkok BTS carriage, which is not a royal wat at 10:00. Pack for the week you booked, then add one modest layer and one dry bag. The 7-Eleven will sell you toothpaste. It will not sell you a Type O adapter at 01:00 in a power cut, and it will not sell you shoulders at the Grand Palace gate.
Four kits, one bag
Light, loose, quick-dry. One long-sleeve for sun and air-con. One modest outfit — knees and shoulders — that can do temples and palaces without a sarong rental. A lightweight linen scarf is the smallest item that solves the most gates; People & Spirit’s Temple etiquette is the rule, the scarf is the tool.
Thailand’s sockets are Type O (you will also meet A/B/C). The UK square pin is Type G. Pack a compact Type O travel adapter in the personal item, not the hold. Dual USB is more use than a fourth plug for a hairdryer you should have left at home.
Shoes: slip-offs for wats, something that can do 15,000 pavement steps, flip-flops for the room and the beach — not for Bangkok. Laces on a 35 °C stone platform is how people skip the shoe rule.
The rest splits by which week you actually have.
| Kit | Add | Leave |
|---|---|---|
| Cool season (roughly Nov–Feb; north especially) | Light fleece or long-sleeve; Inthanon at 2,565 m can want a real layer | A UK winter coat “just in case” |
| Hot season (Mar–May, Songkran 13–15 Apr 2026) | Extra shirts, electrolyte sachets, hat, scarf as sun as well as gate | Foam party costume as your only modest option |
| Monsoon / Andaman wet (often May–Oct on the west) | Compact umbrella, dry bag, one extra quick-dry | A cheap poncho as your only rain plan; suede |
| Islands / longtail | Rash vest, reef-unfriendly-sunscreen alternative, dry bag, slippers that stay on a wet pier | Hard-shell suitcase as the only bag; drone “for the reef” |
| Temples / palaces | Scarf, long trousers or skirt, slip-ons, small umbrella for stone glare | Ripped jeans, football shirt with midriff, climbing shoes for a chedi |
Clothes that work in more than one scene
Bangkok air-con is a climate. Street level is another. The same T-shirt will freeze you on the BTS and cook you in Chatuchak. A light long-sleeve is sun protection at noon and a wrap on the train. Linen and technical shirts beat cotton denim, which stays wet and heavy through a monsoon hour.
One smart-casual that is still modest covers a nicer restaurant and a last-minute palace. You do not need a blazer. You need covered knees that are not beach shorts.
Swim kit that is not your only outfit. A rash vest earns its keep on a boat and on a reef; Land & Sea’s Snorkel or dive is tired of knees on coral. Beaches are not wats; you still need the modest layer in the bag for the temple on the same island.
Rain. A compact umbrella beats a disposable poncho that becomes landfill at the first gust. Monsoon is weather, not a season that cancels the country — but it does cancel boats. Which sea: Which coast. When in the year: When to visit.
If you ride a motorbike, the packing list is suddenly armour, a real helmet, and insurance that says motorbike. That is a Health & safety decision, not a “throw flip-flops on a scooter” aesthetic.
Health, paper, power
Prescriptions in original boxes. A copy of the prescription. DEET or equivalent. Oral rehydration sachets — the 7-Eleven has drinks; sachets are still worth the pocket. Basic plasters, a few analgesics you already know you can take, insect bite cream. Travel insurance PDF offline, and a policy that covers scooters if you will ride one.
Passport: six months validity and a blank page, because the exemption stamp is still a stamp. TDAC completed. UK passports were still getting 60-day visa exemption stamps as of August 2026; a Cabinet rollback to 30 days had been approved but not yet gazetted — confirm on GOV.UK before you fly, not on a Facebook group. Visa & entry.
Power: adapter, a small power bank if you use maps all day, a cable that is not unique to one jacket pocket. Do not pack a travel kettle; hotels and 7-Eleven microwaves exist. Table & Bazaar will teach you the rice box; this page only reminds you that the microwave is in the shop, not in your luggage.
Money: a split of notes, a card, not a single pocket with everything. Money and SIM. SIM in arrivals or day one; the kiosk wants the passport you already packed.
Checklists you can actually tick
Always (the boring core)
| Item | Why |
|---|---|
| Passport, insurance PDF, TDAC done | The trip does not start without them |
| Type O (plus A/C) adapter | UK Type G is the wrong shape |
| Linen / light scarf | Palaces, royal wats, sun, air-con |
| Slip-on shoes + walking shoes | Wat rule + pavement |
| Card + baht notes after first ATM | Stalls and DNP gates |
| Prescriptions in original boxes | Questions at a pharmacy go better |
| Phone, cable, small power bank | Maps, Grab, photos of tickets |
If islands or parks
| Item | Why |
|---|---|
| Roll-top dry bag | Longtail spray, park tickets, phone |
| Rash vest | Sun and less sunscreen in the water |
| Quick-dry extra shirt | One soaking does not end the day |
| Cash in small notes | Park permits |
| Light layer | Doi Inthanon 2,565 m is not Bangkok |
Leave at home
A full winter coat. Five pairs of jeans. A hairdryer. An attitude that the monarchy is a debate club. A drone “just for the reef”. The third pair of trainers. See Etiquette.
The 7-Eleven test
If you forgot sunscreen, contact solution, a cheap umbrella, underwear, or snacks, a city 7-Eleven or a mall will usually save you. A village shop on a wet Tuesday might not have your SPF. Pack the modest layer and the adapter as if 7-Eleven did not exist. Pack toiletries as if it does.
First week on the ground — which airport, which rail line, first wat — is First week. This page is only what should be in the bag when the belt starts moving.
Next
First week, When to visit, Etiquette, Temple etiquette, Which coast.