Thailand is warm for most of the year, but the weather is not the same everywhere. Bangkok is hot and humid, the two coasts get their heaviest rain in different months, and the northern mountains can be cold at night from November to February. This guide explains what to pack for each region and season, and what to wear at temples.
The average temperatures and rainfall figures below are 1991–2020 averages from Thai Meteorological Department (TMD) stations. They are not forecasts, so check the forecast before you travel.
Thailand's Seasons and Climate Zones
TMD divides the year into three seasons:
- Hot season: mid-February to mid-May. Typical daytime highs are 35–39°C, and the hottest days can go above 40°C.
- Rainy season: mid-May to mid-October (the south-west monsoon).
- Cool season: mid-October to mid-February (the north-east monsoon).
| Region | Average temperatures | Wettest months |
|---|---|---|
| Bangkok and central Thailand | Highs 35.7°C in April (hottest), 32.3°C in December | September and October |
| North (Chiang Mai) | January: 30.0°C by day, 15.7°C at night | August and September |
| Andaman coast (Phuket) | Highs 31.8–34.4°C all year | August to October |
| Gulf islands (Koh Samui) | Highs 29.0–32.9°C all year | October to December |
Essentials for Every Region
- Light, breathable clothes in cotton, linen or quick-dry fabric.
- At least one outfit that covers your shoulders and knees, for temples and the Grand Palace.
- A light layer, such as a thin long-sleeved shirt, for air-conditioned malls, buses and trains.
- Comfortable walking shoes, plus sandals with a good grip that can get wet.
- A compact umbrella or a light rain jacket.
- Sunscreen, a hat, sunglasses, insect repellent, your personal medicines and a reusable water bottle.
- A plug adapter if you need one. Thai sockets take plug types A, B, C and O, and mains voltage is 230 V, so check that your chargers work at 230 V.
- A small dry bag for your phone and passport on boats and rainy days.
If you book an airport pickup with Smile Taxi Service, you can ask for a free 500 MB Thailand eSIM when you book.
Packing for Bangkok and Central Thailand
Bangkok is hot all year. Even in December and January, the average night-time low is about 23°C, so you will rarely need a jacket outdoors. April is the hottest month, with an average high of 35.7°C. Bangkok's record highs are 40.0°C in April and 41.0°C in May, so 40°C is possible but rare.
September is the wettest month, with about 336 mm of rain. Even then, Bangkok averages about 18 rain days, so many days stay partly dry. In the rainy season, plan outdoor sightseeing for the morning and keep indoor options for later in the day.
Pattaya is drier than Bangkok, with about 1,106 mm of rain a year. Its wettest month is October, with about 225 mm.
Packing for Beach Destinations
Both coasts are warm all year; the main difference is when the rain falls.
Andaman coast: Phuket, Krabi and the islands
In Phuket, February is the driest month, with about 24 mm of rain. From May to October, every month averages more than 200 mm, and September is the wettest, with about 350 mm.
Check park closures before you plan a boat trip:
- The Similan Islands are closed from 16 May to 14 October every year. The 2026–27 season opens on 15 October 2026.
- Maya Bay on Koh Phi Phi Le is closed every year from 1 August to 30 September and reopens on 1 October 2026. Phi Phi boat tours keep running during the closure, but they may not enter the bay.
Gulf islands: Koh Samui
On Koh Samui, the wettest months are October to December. November is the wettest, with about 445 mm of rain, and February to September is the drier part of the year. For 2026, TMD expects the rain on the Gulf side of the south (Samui, Nakhon Si Thammarat, Hat Yai and Songkhla) to continue until December. If you travel there from October to December, keep a spare day or two in your plans. In late November 2025, floods after Cyclone Senyar hit Songkhla hardest.
Beach packing list
- Swimwear and a light cover-up.
- Sunscreen without oxybenzone. Since August 2021, Thailand has banned sunscreens with coral-harmful chemicals, including oxybenzone, in all marine national parks, with fines of up to 100,000 THB. Check the label before you pack.
- Seasickness tablets if you need them.
To reach the coast, see how to get from Bangkok to Phuket and how to get from Bangkok to Koh Samui.
Packing for Northern Thailand and the Mountains
Chiang Mai has warm days all year. In January, the average high is 30.0°C and the average low is 15.7°C, and the city's record low is 3.7°C. From November to February, pack a fleece or light jacket and long trousers for the evenings.
April is the hottest month, with an average high of 36.7°C. March and April are also the smog season in the north: on 4 April 2026, Chiang Mai was declared an emergency disaster zone for air pollution. In those months, check PM2.5 levels on the free Air4Thai or IQAir AirVisual apps before you plan outdoor days. August is the wettest month, with 223.3 mm of rain on average, so bring a rain jacket and shoes with a good grip.
Doi Inthanon is Thailand's highest peak, at 2,565 m. On 27 November 2025, the summit was 2°C, the coldest point was -2.3°C, and there was frost for the fourth morning in a row; the park warned that frost can make the summit road slippery. For Doi Inthanon, Phu Kradueng or Phu Ruea in December or January, bring a warm jacket, long trousers and closed shoes.
Doi Inthanon's Kew Mae Pan nature trail is closed from June to October and reopens on 1 November, and a local guide is required. Phu Kradueng National Park is closed from June to September.
Smile Taxi Service runs a full-day Chiang Mai + Doi Tour of up to 10 hours (see the tours page): 3,300 THB by sedan, 3,500 THB by SUV, 4,000 THB by van and 4,500 THB by VIP van. To plan the journey north, see how to get from Bangkok to Chiang Mai.
Seasonal Adjustments
Hot season: pack your lightest clothes and a hat. Drink water often and rest in the shade or in air conditioning at midday. Confusion and hot, dry skin are signs of heat stroke; call 1669 for a medical emergency.
Rainy season: add quick-dry clothes and an umbrella. TMD expects the 2026 rains in upper Thailand to end about mid-October. Do not wade or drive through floodwater, and do not shelter under trees in a thunderstorm. If a T-Alert warning appears on your phone, follow its instructions.
Cool season: Bangkok and the beaches stay warm, so pack summer clothes. Add layers for the north and a warm jacket for the mountains.
Dressing for Temples and the Grand Palace
The Grand Palace in Bangkok has a strict dress code. Cover your shoulders and knees. Sleeveless shirts, crop tops, see-through tops, shorts, tight trousers or leggings, miniskirts and torn clothes are not allowed. As of September 2026, visitors who arrive underdressed can borrow a sarong or shawl at the entrance, but check the terms with the Grand Palace, or simply arrive dressed correctly. The same outfit is a safe choice for other temples.
The Grand Palace is open daily from 08:30 to 16:30, and tickets are sold from 08:30 to 15:30. Admission is 500 THB.
During the royal cremation ceremonies for Queen Sirikit The Queen Mother, from 15 to 19 December 2026, expect crowds and road closures around Sanam Luang and the Grand Palace. Check before you plan a visit to that area.
For a rooftop bar, pack one smart-casual outfit. Sky Bar at lebua in Bangkok allows tailored shorts and elegant sandals, but it does not allow athletic wear, swimwear, sleeveless shirts for men or flip-flops.
Luggage and Airport Transfers
When you book an airport transfer, count your bags as well as your passengers. Smile Taxi Service vehicles take:
| Vehicle | Passengers | Bags |
|---|---|---|
| Sedan (Toyota Camry or similar) | up to 3 | 2 |
| SUV (Toyota Fortuner or similar) | up to 5 | 4 |
| Van (Toyota Commuter or similar) | up to 7 | 5 |
Fares are fixed, per vehicle (not per person), one way, with expressway tolls included. For example:
- Suvarnabhumi Airport to Pattaya: sedan 1,200 THB, SUV 1,500 THB, van 1,800 THB. Book a sedan from Suvarnabhumi to Pattaya.
- Phuket Airport to Patong Beach: sedan 1,000 THB, SUV 1,100 THB, van 1,400 THB. Book a sedan from Phuket Airport to Patong Beach.
Airport pickups include 60 minutes of free waiting, counted from the actual landing time. You pay the driver in cash (THB) at the end of the trip; if you can only pay by card, message the team for a PayPal payment link (a 5% fee is added). Cancellation is free up to 24 hours before pickup. After that, a cancellation or change costs 25% (less than 24 h), 35% (less than 12 h) or 50% (less than 2 h) of the price, and a no-show 100%, also when you pay the driver in cash (details). See all routes on the price list.
What to Leave at Home
- Heavy jeans and thick jumpers, unless you are going to the northern mountains in the cool season.
- More shoes than you need: walking shoes and sandals are enough for most trips.
- Large amounts of basics. Light clothes, sandals and toiletries are easy to buy in Thai cities.
Save these numbers before you go: police 191, Tourist Police 1155, medical emergency 1669, TMD weather hotline 1182, the disaster hotline (DDPM) 1784 and the TAT call centre 1672. For forecasts and rain radar, see the Thai Meteorological Department website.
FAQ
Do I need warm clothes for Thailand? Only for the north and the mountains, from about November to February. Chiang Mai averages 15.7°C at night in January, and mountain summits can drop below 0°C.
What plug adapter do I need? Thai sockets take plug types A, B, C and O, and the mains voltage is 230 V.
Can I bring any sunscreen for a Similan or Phi Phi trip? Not one with oxybenzone. It is banned in marine national parks, with fines of up to 100,000 THB.
Do tourists need to wear black for royal mourning? No. The 90-day request to wear subdued colours ended in early 2026 and was never a rule for visitors. Neutral, modest clothes are respectful around the December 2026 cremation.
To travel with all your luggage from the airport to your hotel, book your transfer or message us on WhatsApp or LINE.