Heavy rain and strong waves in South Dec 11–16, unsettled weather in upper Thailand
Thai Met Department warns of heavy to very heavy rain and 2–3m waves in the South from December 11–16, while upper Thailand faces storms then a 2–4°C temperature drop
The Thai Meteorological Department has issued Weather Warning No.4 (377/2568) for heavy to very heavy rain in the South and strong winds and waves in the Gulf of Thailand, with impacts expected from December 11–16 2025. Upper Thailand will also see unstable weather with thunderstorms followed by a sharp drop in temperature.
From December 11–13, rain will increase across the South, with heavy rain in many areas of Prachuap Khiri Khan, Ranong, Phang Nga, Trang and Satun, and heavy to very heavy rain in Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat.
This is due to a low-pressure cell over the lower South China Sea moving across the southern tip of Vietnam, the Gulf of Thailand and southern Thailand.
From December 14–16, the lower South will continue to see heavy rain in many areas, particularly in Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, Narathiwat, Trang and Satun, as the north-easterly monsoon over the Gulf of Thailand and the South strengthens.
Winds and waves in the Gulf of Thailand and Andaman Sea will also intensify.
In the lower Gulf of Thailand, waves will be 2–3 metres high, rising to over 3 metres in areas with thunderstorms.
In the upper Gulf, waves will be around 2 metres.
In the Andaman Sea, offshore waves will be over 2 metres, and higher than 2 metres in thundery areas.
The public in southern provinces is advised to beware of heavy rain and accumulated rainfall, which may cause flash floods and run-off, especially in foothill areas near waterways and in low-lying zones. Mariners in the Gulf of Thailand and Andaman Sea should proceed with caution and avoid sailing in thundery areas, while small boats in the lower Gulf are advised not to leave shore.
For upper Thailand, the department forecasts unsettled weather with isolated thunderstorms between December 11–13, due to easterly winds bringing moisture over the region. After that, temperatures will fall by 2–4°C, with cool to cold conditions and strong winds, as a rather strong high-pressure system / cold air mass from China spreads over Thailand.
People in upper Thailand are advised to take care of their health during the changing weather, while farmers should prepare for and take precautions against potential damage to crops.
The public is urged to follow further announcements from the Thai Meteorological Department and check updates via the department’s website http://www.tmd.go.th or 24-hour hotlines.
