Thailand Weather in May 2025: Travel Tips for First Visitors

This article covers the weather in May in Thailand, including average temperatures, rainfall, and tips on what to wear and places to go.

Thailand Weather in May Overview

• Average temperature range: 29–35°C (84–95°F)
• Rainfall: 84 mm (10 inches)
• Rainy days: 25
• Sunny days: 5

As one of the hottest months in Thailand, the temperature in many places of Thailand can reach 35°C (95°F) on average daily. With an average of 16 rainy days, Thailand is quite wet during May. Sometimes, it rains cats and dogs in some places. So, remember to take an umbrella and waterproof jackets.

Thailand's Regional Weather

Bangkok and Central Thailand: May gets extremely humid as the hot season gives way to the wet season. The rainfall starts to increase toward the end of the month with more than half of the month seeing short, thunderous bursts that last for about an hour.

Northern Thailand: Compared to central Thailand, Chiang Mai and Chiang Rai are much cooler with lower humidity. By the end of May, everything looks a lot greener than in the previous few months.

Southern Thailand: Rainfall during May is much lower on the Gulf of Thailand than on the Andaman Coast. The Andaman Coast, where Phuket and Krabi are situated, starts to see the effects of the southwest monsoon, which begins in late May, but it isn't in full swing until June.

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The Best Places to Visit in Thailand in May

May is one of the hottest months in Thailand. We are selecting some suitable places in May for you. Read more about the best places to visit in Thailand in May.

1. Bangkok

Although it is quite hot during May, Bangkok is a must-visit city if you are traveling to Thailand. There are numerous historical attractions that are worth visiting including the famous Grand Palace, Bangkok National Museum, which is a mecca for Thai history and art, and Jim Thompson House Museum, a beautifully designed Sukhothai wooden house set in the heart of Bangkok's shopping district.

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2. Chiang Mai

Located in the mountainous north, Chiang Mai is a good place for trekking among the greenery and villages and climbing some of the tallest mountains in Thailand or just visiting the elephant sanctuaries. Tourists can also take cooking classes and spa treatments, neither of which are weather dependent.

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3. Chiang Rai

You can escape the heat and humidity during May in Chiang Rai by visiting the Huai Kaew and Huai Mae Sai waterfalls to cool down.

There are also numerous air-conditioned cafés and restaurants in town where you can grab a traditional iced tea or an authentic Lanna meal when the heat gets too much to handle.

As the rainfall starts to increase toward the end of the month, the already stunning Chiang Rai valleys and mountain ranges get greener and even more beautiful than before.

4. Hua Hin

Of all the mainland beach resort towns, Hua Hin has least rainfall and is a great place to spend your vacation in May. It's close enough to Bangkok that you don't have to fly and has a range of beaches and resorts to suit any taste.

5. Koh Samui

Koh Samui, along Thailand's Gulf Coast, does not see the full effect of the southwest monsoon until September, which makes May a great month to visit the island.

With the deteriorating weather comes less than ideal snorkeling and diving conditions. While diving is still possible on the sheltered east coast, it becomes far less practical on the west coast.

6. Phuket

Although it is hot and often rains in May, you can still enjoy the beaches in late afternoon or early morning when the temperature is not unbearable. Phuket and Krabi sometimes experience torrential downpours and strong winds, meaning some boat services to other islands can be suspended.

Crowding and Costs in May

Due to its extreme heat and humidity, few people choose May to visit Thailand. Hotel and attraction rates are quite low during May. If you are looking for discounted tours in Thailand, May is a good time to save money for traveling.

Clothes to Wear in May

As one of the hottest months in Thailand, light and cool clothing is most comfortable to wear in May, including shorts, skirts, T-shirts, light trousers, and caps. It often rains in May, so umbrellas, light raincoats, rubber boots or sandals are needed from time to time.

If you are going to visit temples in Thailand, remember to wear long-sleeved clothes, and long skirts or trousers out of respect.

Monthly Weather and Travel Information for Thailand

Learn about the weather in Thailand for 12 months and find out the best places to visit each month.

Tour Thailand with Us

Are you planning a May getaway to Thailand? If so, make sure to get in touch with us now and we will put together a detailed itinerary for you to make sure that you get the most out of your trip to paradise.