Southern Thailand braces for heavy rain as seas turn rough, TMD warns
A low-pressure system and a strengthening northeast monsoon are set to bring widespread downpours to southern provinces through December 16, with rough seas and waves of up to three metres in the Gulf of Thailand.
- The Thai Meteorological Department (TMD) has forecast heavy rain for Southern Thailand from December 12-16, caused by a low-pressure cell and a strengthening northeast monsoon.
- Seas in the Gulf of Thailand and the Andaman Sea are expected to become rough, with waves reaching 2-3 meters and exceeding 3 meters during thunderstorms.
- Residents have been warned of potential flash floods and runoff, while mariners are advised to navigate with caution and small boats in the lower Gulf have been told to stay ashore.
The Thai Meteorological Department (TMD) said heavy rain is forecast across the South on December 12-13, with downpours expected in Prachuap Khiri Khan, Songkhla, Ranong, Phang Nga and Krabi, and heavy rain in Chumphon, Surat Thani, Nakhon Si Thammarat and Phatthalung due to a low-pressure cell covering the region.
From December 14-16, 2025, the lower South is set to see continued heavy rain in Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, Narathiwat, Krabi, Trang and Satun, as the northeast monsoon strengthens over the Gulf of Thailand and the South.
Seas will also become rougher, with waves of 2-3 metres in the lower Gulf and over 3 metres in thunderstorms.
The upper Gulf will see waves of around 2 metres, while the Andaman Sea will have waves of over 2 metres offshore, rising above 2 metres in stormy areas.
The TMD urged residents to watch for flash floods and runoff from heavy and accumulated rainfall, especially on hillsides near waterways and in low-lying areas.
Mariners in both the Gulf of Thailand and the Andaman Sea were advised to navigate with caution and avoid stormy areas, while small boats in the lower Gulf were told to stay ashore.
Meanwhile, upper Thailand will see unsettled conditions on December 12-13, with isolated thunderstorms as easterly winds bring moisture northwards.
Temperatures are then expected to drop by 2-4°C, with cooler to cold conditions and stronger winds as a fairly strong high-pressure system from China spreads over the country.
The public was advised to take care of their health as the weather shifts, while farmers were urged to protect crops from possible damage.
The bulletin was issued at 5pm on December 12, 2025, with the next update due at 11pm the same day.
