Thailand in May: ⚠️ a low-season month, with caveats. The monsoon arrives: more than 200 mm (7.9 in) of rain in Bangkok and Phuket, and the heat is still intense (35.1 °C (95 °F) in the afternoon in Bangkok). The Gulf remains the best beach option (Ko Samui, 132 mm (5.2 in); Hua Hin, 96 mm (3.8 in)). In return, prices and crowds are among the lowest of the year. For the monsoon’s arrival, our page Thailand in June covers the following month region by region.
May marks the end of the hot season and the start of the rainy season. To work out where to go, we compared the official normals of eight cities and calculated the probability of a rain day. Overview: best time to visit Thailand; itineraries: our Thailand travel guide.
Thailand in May: key facts
- Verdict: ⚠️ low season; ✅ in the Gulf
- Bangkok: 35.1 °C (95 °F) in the afternoon, 26.9 °C (80 °F) at night, 217 mm (8.5 in), about 12 rain days
- Beach: Ko Samui (132 mm (5.2 in)) and Hua Hin (96 mm (3.8 in)) rather than Phuket (237 mm (9.3 in), 16 days)
- North: end of the burning season, rain returns (168 mm (6.6 in) in Chiang Mai)
- Pluses: low prices, few people, May festivals
- Entry: visa-exempt tourist stays of up to 30 days per entry for US and UK citizens since 15 September 2026 (Tourism Authority of Thailand); TDAC arrival card mandatory
Thailand weather in May: region by region
| City | Region | Max °C (°F) | Min °C (°F) | Rain mm (in) | Rain days | Chance of a rain day | Verdict |
|---|---|---|---|---|---|---|---|
| Ko Samui | Gulf (islands) | 32.9 °C (91 °F) | 25.7 °C (78 °F) | 132 mm (5.2 in) | 11.0 | 35% | ✅ |
| Surat Thani | Gulf (mainland) | 34.5 °C (94 °F) | 24.3 °C (76 °F) | 151 mm (5.9 in) | 13.1 | 42% | ⚠️ |
| Hua Hin | Gulf (west coast) | 33.7 °C (93 °F) | 26.3 °C (79 °F) | 96 mm (3.8 in) | 8.5 | 27% | ✅ |
| Pattaya | Gulf (east coast) | 32.7 °C (91 °F) | 26.6 °C (80 °F) | 121 mm (4.8 in) | 9.0 | 29% | ⚠️ |
| Bangkok | Central | 35.1 °C (95 °F) | 26.9 °C (80 °F) | 217 mm (8.5 in) | 12.4 | 40% | ⚠️ |
| Chiang Mai | North | 34.7 °C (94 °F) | 24.2 °C (76 °F) | 168 mm (6.6 in) | 12.0 | 39% | ⚠️ |
| Chiang Rai | Far north | 33.5 °C (92 °F) | 23.0 °C (73 °F) | 226 mm (8.9 in) | 14.5 | 47% | ⚠️ |
| Phuket | Andaman | 33.2 °C (92 °F) | 26.1 °C (79 °F) | 237 mm (9.3 in) | 15.7 | 51% | ❌ |
Destination de Voyage calculation based on these normals: on a 7-day stay in May, you can expect on average about 4 days with rain in Phuket, 3 in Bangkok, 2 in Ko Samui and 2 in Hua Hin. May also has some of the warmest nights of the year: 26–27 °C (79–81 °F) in Bangkok, Hua Hin and Pattaya.
May compared with April and June
| Station | April | May | June |
|---|---|---|---|
| Bangkok | 93 mm (3.7 in) / 5.4 d | 217 mm (8.5 in) / 12.4 d | 199 mm (7.8 in) / 13.4 d |
| Chiang Mai | 54 mm (2.1 in) / 4.7 d | 168 mm (6.6 in) / 12.0 d | 118 mm (4.6 in) / 11.6 d |
| Phuket | 135 mm (5.3 in) / 9.6 d | 237 mm (9.3 in) / 15.7 d | 249 mm (9.8 in) / 15.9 d |
| Ko Samui | 83 mm (3.3 in) / 6.1 d | 132 mm (5.2 in) / 11.0 d | 134 mm (5.3 in) / 10.3 d |
The switch from April to May is the most abrupt of the year: the number of rain days roughly doubles in Bangkok (5.4 → 12.4) and more than doubles in Chiang Mai (4.7 → 12.0). June then looks much like May. If you travel in early May, conditions are often still close to April’s; by the end of the month, the monsoon has usually set in. For the end of the monsoon, compare with our page Thailand in October.
Where to go in May
The Gulf: the best beach option
Ko Samui, Ko Phangan and Ko Tao are in their favourable season, which runs from February to September according to our when-to-go page. Hua Hin, on the mainland, is the least rainy station in our table (96 mm (3.8 in)). See when to go to Ko Samui and our Ko Phangan and Ko Tao guides.
The Andaman coast: start of the monsoon
In Phuket, Krabi or Ko Lanta, the southwest monsoon sets in: nearly 16 rain days in Phuket and the sea gets rougher. The Similan Islands generally close from mid-May to mid-October (dates set by the Department of National Parks). See when to go to Phuket.
Bangkok and the north
Bangkok is still fine to visit: storms late in the day, heavy heat. In the north, the May rains end the burning season that often degrades the air from February to April, according to our when-to-go page. See when to go to Bangkok and when to go to Chiang Mai.
What to do in Thailand in May
- Beaches in the Gulf: Ko Samui, Ko Phangan, Ko Tao, Hua Hin.
- Khao Sok and Cheow Lan Lake: recommended by the Tourism Authority of Thailand in May, at the start of the rainy season.
- Pink dolphins: boat trips in Nakhon Si Thammarat (Laem Prathap), cited by the Tourism Authority for this month.
- Seasonal fruit: orchards open to visitors in Rayong and Chanthaburi provinces.
- Avoid: a beach stay in Phuket counting on a calm sea, and sightseeing in the heat of the afternoon.
Events in May
According to the Tourism Authority of Thailand, May is the month of the rocket festivals (Bun Bang Fai) in the northeast: the one in Yasothon is held every year on the second weekend of May. The Royal Ploughing Ceremony in Bangkok and Visakha Bucha, the most important Buddhist festival, take place in May or early June depending on the year, on dates that follow the lunar calendar. 1 and 4 May are public holidays. Check the dates for your year with the Tourism Authority.
Crowds, prices and booking
May is one of the months with low crowds and low prices on the mainland according to our calendar: it is one of the best times for a budget trip.
What to pack for Thailand in May
- Very light, breathable clothing
- A poncho or light rain jacket
- Sunscreen, hat, water bottle
- Insect repellent
- A waterproof pouch for your phone
- Clothing that covers shoulders and knees for temples
Entry requirements and safety
US citizens: according to the U.S. Department of State (page last updated August 20, 2026), pre-arrival online registration is required. A passport valid for at least six months beyond arrival is strongly recommended, and you may be asked for an onward or return ticket or proof of funds.
UK citizens: according to the UK FCDO (GOV.UK, updated 12 October 2026), your passport must be valid for at least 6 months after arrival, with 1 blank page. From 15 September 2026, visa-exempt entry is up to 30 days, for tourism only. Visa-exempt entries over land borders are normally limited to 2 per calendar year. You may need proof of funds (10,000 THB per person or 20,000 THB per family) and onward travel. The overstay fine is 500 THB a day, up to 20,000 THB.
The Thailand Digital Arrival Card (TDAC) has been mandatory for all foreign nationals since 1 May 2025 and can be completed within the 3 days before arrival. The U.S. State Department page (last updated August 20, 2026) still mentions 60 days, but it predates the change: under the Thai rules in force since 15 September 2026, US citizens are also limited to 30 days (Tourism Authority of Thailand, 1 September 2026). Check with the Royal Thai Embassy in Washington before you travel.
Safety: the FCDO advises against all but essential travel to Pattani, Yala, Narathiwat and parts of southern Songkhla (Thailand–Malaysia border), and to areas within 20 km (12 mi) of the Cambodian land border; land crossings with Cambodia are suspended. Time difference in May: Thailand (UTC+7, no daylight saving) is 6 hours ahead of London and 11 hours ahead of New York.
Climate note: according to the UK FCDO (GOV.UK, updated 12 October 2026), the rainy season is generally from May to October, and from November to March on Koh Samui and in south-east Thailand.
If May does not suit you
Previous month: Thailand in April is drier but hotter, with Songkran. For a full circuit in dry weather, aim for November to February. Other destinations in May: Bali in May, at the start of the dry season. All our ideas: where to go in May.
Frequently asked questions
Is May a good time to visit Thailand?
Yes for a budget trip, heading to the Gulf for the beach. You have to accept the heat and frequent storms in Bangkok, the north and on the Andaman side.
What is the weather like in Thailand in May?
Very hot: 33–35 °C (91–95 °F) in the afternoon, 23–27 °C (73–81 °F) at night. It rains on 12 days on average in Bangkok and nearly 16 in Phuket.
Where are the best beaches in May?
In the Gulf: Ko Samui, Ko Phangan, Ko Tao, or Hua Hin on the mainland (96 mm (3.8 in) of rain).
Is May the rainy season in Thailand?
It is the start of it: the rainy season runs from mid-May to October over most of the country.
Are the Similan Islands open in May?
They generally close from mid-May to mid-October. Check the dates with the Department of National Parks.
How long can you stay without a visa?
No visa is needed for tourism stays of up to 30 days per entry: since 15 September 2026, this exemption applies to both US and UK citizens, according to the Tourism Authority of Thailand (1 September 2026) and the UK FCDO (GOV.UK, updated 12 October 2026). The U.S. State Department page (last updated August 20, 2026) still mentions 60 days, but it predates the change. Check with the Royal Thai Embassy before you travel. The TDAC digital arrival card is mandatory.
Our sources
- Thai Meteorological Department, 1991–2020 climate normals published by the World Meteorological Organization (NOAA NCEI archive): Bangkok, Chiang Mai, Chiang Rai, Hua Hin, Pattaya, Phuket, Ko Samui, Surat Thani
- Tourism Authority of Thailand (French-language site tourismethai.fr), “May in Thailand”, accessed 23 October 2026
- Calendars from our page on the best time to visit Thailand
- Entry requirements, safety and health checked on 24 October 2026: Tourism Authority of Thailand, TAT Newsroom, 1 September 2026: new 30-day visa exemption rules from 15 September 2026; UK FCDO, GOV.UK foreign travel advice: Thailand (updated 12 October 2026); U.S. Department of State, travel.state.gov: Thailand (last updated August 20, 2026)
- Our methodology
Updated October 2026.