Rough-sea warning issued for Phuket as 39 Thai provinces face flood risk
All Phuket districts are under a rough-sea warning from 18-21 August 2026, with waves in the upper Andaman Sea forecast to exceed 3 metres during thunderstorms.
All districts in Phuket have been placed under a rough-sea warning from 18-21 August 2026, while authorities monitor flash-flood, landslide and waterlogging risks across 39 other Thai provinces.
The Department of Disaster Prevention and Mitigation (DDPM) said the warning followed a Thai Meteorological Department forecast of heavy to very heavy rain caused by a monsoon trough over northern and upper northeastern Thailand and a strong south-westerly monsoon over the Andaman Sea, Thailand and the Gulf of Thailand.
Sea conditions in the upper Andaman Sea are expected to strengthen from 19-21 August, with waves of 2-3 metres and higher than 3 metres during thunderstorms. Waves in the lower Andaman Sea and upper Gulf of Thailand could reach about 2 metres, rising above that level in thundery areas.
The rough-sea alert also covers parts of Ranong and Phang Nga. In Phang Nga, the affected districts are Khura Buri, Takua Pa, Thai Mueang, Takua Thung and Ko Yao.
The DDPM has instructed authorities to monitor weather, rainfall and local water levels, deploy response teams and machinery in vulnerable areas, and prepare temporary shelters where necessary. Locations with accumulated rainfall above 90 millimetres in 24 hours and areas with a history of repeated flooding are to receive particular attention.
Authorities have also been told to monitor caves, waterfalls and other natural tourist attractions, issuing warnings or closing access if conditions become dangerous. In coastal areas, agencies are to install warning signs, prevent visitors from entering the water during dangerous conditions and advise boat and passenger-transport operators to exercise caution. Boat services may be suspended if conditions deteriorate.
The public is advised to follow official weather and disaster announcements. Assistance is available through the THAI DISASTER ALERT application, the LINE account @1784 DDPM and the 1784 disaster prevention hotline.
