Bangkok faces 60% rain and heavy falls as flood risk rises nationwide

The Thai Meteorological Department’s weather forecast for Sunday (May 17, 2026) warns that Bangkok and surrounding provinces will see thunderstorms in over 60% of areas, with heavy rain in some places.

All regions of Thailand are expected to see more rain, which could trigger flash floods and forest run-off.

Over the next 24 hours, Thailand will continue to experience rain, with heavy rain in some places and very heavy rain in parts of the South’s west coast.

This is due to a rather strong southwest monsoon prevailing over the upper Andaman Sea and Thailand.

People are advised to be aware of dangers from heavy to very heavy rain and accumulated rainfall, which could cause flash floods and forest run-off, especially in foothill areas near waterways and low-lying areas.

They are also advised to take care of their health during changing weather conditions.

Waves in the upper Andaman Sea are rather strong, at 2-3 metres and more than 3 metres in thundershowers.

In the lower Andaman Sea and the upper Gulf of Thailand, waves are 1-2 metres and more than 2 metres in thundershowers.

Mariners in these areas are advised to navigate with caution and avoid sailing in thundershowers.

Small boats in the upper Andaman Sea should remain ashore.

Weather forecast for Thailand from 6am on Sunday (May 17) to 6am on Monday (May 18)

Bangkok and surrounding provinces

• Thunderstorms in 60% of areas, with heavy rain in some places.
• Lowest temperature: 26-28 degrees Celsius
• Highest temperature: 35-37 degrees Celsius
• Southwesterly winds: 10-20 km/h

North

• Thunderstorms in 40% of areas, with heavy rain in some places in Tak, Kamphaeng Phet, Phitsanulok and Phetchabun.
• Lowest temperature: 23-26 degrees Celsius
• Highest temperature: 34-37 degrees Celsius
• Southwesterly winds: 10-20 km/h

Northeast

• Thunderstorms in 60% of areas, with heavy rain in some places in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Yasothon, Amnat Charoen, Si Sa Ket and Ubon Ratchathani.
• Lowest temperature: 24-27 degrees Celsius
• Highest temperature: 33-36 degrees Celsius
• Southwesterly winds: 10-20 km/h

Central region

• Thunderstorms in 60% of areas, with heavy rain in some places in Nakhon Sawan, Uthai Thani, Chai Nat, Kanchanaburi, Ratchaburi, Nakhon Pathom and Samut Sakhon.
• Lowest temperature: 24-26 degrees Celsius
• Highest temperature: 35-38 degrees Celsius
• Southwesterly winds: 10-20 km/h

East

• Thunderstorms in 60% of areas, with heavy rain in some places in Nakhon Nayok, Prachin Buri, Chachoengsao, Chon Buri, Rayong, Chanthaburi and Trat.
• Lowest temperature: 25-29 degrees Celsius
• Highest temperature: 32-36 degrees Celsius
• Southwesterly winds: 15-35 km/h
• Waves are 1-2 metres high and more than 2 metres in thundershowers.

South, east coast

• Thunderstorms in 60% of areas, with heavy rain in some places in Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani and Nakhon Si Thammarat.
• Lowest temperature: 23-26 degrees Celsius
• Highest temperature: 34-36 degrees Celsius
• Southwesterly winds: 15-35 km/h
• Waves are about 1 metre high, rising to 1-2 metres offshore and more than 2 metres in thundershowers.

South, west coast

• Thunderstorms in 60% of areas, with heavy to very heavy rain in some places in Ranong, Phang Nga, Phuket, Krabi and Trang.
• Lowest temperature: 23-26 degrees Celsius
• Highest temperature: 30-34 degrees Celsius
• From Phang Nga northwards: southwesterly winds of 20-40 km/h, with waves 2-3 metres high and more than 3 metres in thundershowers.
• From Phuket southwards: southwesterly winds of 15-35 km/h, with waves 1-2 metres high and more than 2 metres in thundershowers.