TMD warns of 60-70% rain, strong winds and flash floods in Thailand

The Thai Meteorological Department (TMD) has warned of weather conditions on Friday (May 15, 2026), with rain forecast in 60-70% of areas in the North, Central region and South, as well as Bangkok.

It announced a list of 52 provinces to prepare for the impact of strong winds and monitor flash floods and forest run-off during the period of changing weather.

In its 24-hour forecast, the department said rainfall would increase across Thailand, with heavy rain in some places and very heavy rain in parts of the North, Central region and upper South, because the south-west monsoon is prevailing over the Andaman Sea, Thailand and the Gulf of Thailand.

The public has been advised to beware of thunderstorms, heavy rain and accumulated rainfall, which could cause flash floods and forest run-off.

Particular caution is urged in foothill areas near waterways and low-lying areas.

Farmers should strengthen fruit trees and prepare measures to prevent possible damage to agricultural produce and livestock, while people should take care of their health during changing weather.

In the upper Andaman Sea, wind and waves are moderate, with waves about 2 metres high and more than 2 metres in the thundershower areas.

Mariners have been advised to sail with caution and avoid areas with thundershowers.

Weather forecast for Thailand from 6am on Friday (May 15) to 6am on Saturday (May 16)

Northern region

• Thundershowers in 70% of the area, with heavy to very heavy rain in some places: Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae, Uttaradit, Tak, Kamphaeng Phet, Phitsanulok and Phetchabun.
• Minimum temperature: 22-26 degrees Celsius.
• Maximum temperature: 32-35 degrees Celsius.
• South-westerly winds: 10-15 km/h.

Northeastern region

• Thundershowers in 60% of the area, with heavy rain in some places: Loei, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Chaiyaphum, Mukdahan, Amnat Charoen, Si Sa Ket and Ubon Ratchathani.
• Minimum temperature: 24-27 degrees Celsius.
• Maximum temperature: 34-36 degrees Celsius.
• South-westerly winds: 10-20 km/h.

Central region

• Thundershowers in 60% of the area, with heavy to very heavy rain in some places: Nakhon Sawan, Uthai Thani, Kanchanaburi and Ratchaburi.
• Minimum temperature: 25-27 degrees Celsius.
• Maximum temperature: 35-36 degrees Celsius.
• South-westerly winds: 10-20 km/h.

Eastern region

• Thundershowers in 60% of the area, with heavy rain in some places: Rayong, Chanthaburi and Trat.
• Minimum temperature: 25-27 degrees Celsius.
• Maximum temperature: 33-35 degrees Celsius.
• South-westerly winds: 15-35 km/h.
• The sea will have waves 1-2 metres high, and more than 2 metres in thundershower areas.

Southern region (East Coast)

• Thundershowers in 60% of the area, with heavy to very heavy rain in some places: Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat.
• Minimum temperature: 23-26 degrees Celsius.
• Maximum temperature: 33-35 degrees Celsius.
• South-westerly winds: 15-30 km/h.
• The sea will have waves about 1 metre high, and more than 2 metres in thundershower areas.

Southern region (west coast)

• Thundershowers in 70% of the area, with heavy rain in some places: Ranong, Phang Nga, Phuket, Krabi, Trang and Satun.
• Minimum temperature: 23-26 degrees Celsius.
• Maximum temperature: 32-34 degrees Celsius.
• From Phang Nga northwards: south-westerly winds of 20-35 km/h.
• The sea will have waves about 2 metres high, and more than 2 metres in thundershower areas.
• From Phuket southwards: south-westerly winds of 15-30 km/h.
• The sea will have waves about 1 metre high, and more than 2 metres in thundershower areas.

Bangkok and vicinity 

• Thundershowers in 60% of the area.
• Minimum temperature: 25-27 degrees Celsius.
• Maximum temperature: 34-36 degrees Celsius.
• South-westerly winds: 10-20 km/h.