Flooding persists in nine southern provinces, affecting 800,000 people, with Songkhla the worst hit, officials said on Saturday.
A total of 101 districts have reported varying degrees of water inundation in Nakhon Si Thammarat, Narathiwat, Pattani, Phatthalung, Satun, Songkhla, Surat Thani, Trang and Yala, said Chayapol Thitisak, director-general of the Department of Disaster Prevention and Mitigation.
Officials have been building shelters, distributing consumer products, providing power and water, deploying boats and portable toilets to help those in need, he said.
Conditions are still critical in four districts of Songkhla facing Songkhla Lake as water flows in from Phatthalung province.
Local authorities in the four districts -- Krasae Sin, Ranot, Sathing Phra and Singha Nakhon -- are operating pumps to speed up drainage of water from the lake into the Gulf of Thailand but they say flooding could persist for up to a month.
In Pattani, water from Yala province was flowing into the Pattani River which then overflowed to commercial districts. Downtown shops were closed from Friday night.
In Narathiwat, the Sungai Kolok River was overflowing in riverside areas of Tak Bai district, fed by runoff from the San Kala Khiri mountain range. Flood levels exceeded two metres on some locations.
The Meteorological Department was forecasting more heavy rain in some areas of Nakhon Si Thammarat, Narathiwat, Pattani, Phatthalung, Songkhla and Yala on Saturday.