All southern provinces are warned to brace for torrential rain and possible sudden flooding this week as a tropical depression moves closer to the mainland.
The latest weather warning released by the Meteorological Department on Monday was for Prachuap Khiri Khan and provinces to the south along the Gulf of Thailand. Heavy rain and flash floods are forecast until Wednesday, with the storm expected to make landfall in Surat Thani on Tuesday.
Provinces on the Andaman Coast will also be blanketed by rain from Tuesday to Thursday as the depression moves across the peninsula.
"Residents in these areas should beware of severe conditions and possible flash floods," department director-general Wanchai Sakudomchai said.
Some areas in the South, including Songkhla and Nakhon Si Thammarat, have already been flooded.
The rain is a spillover from typhoon Damrey, which has wreaked havoc in Vietnam, killing at least 44 people.
High waves and rough seas are forecast for the Gulf of Thailand. The regional office of the Marine Department in Pattaya ordered the suspension of ferry services between the resort city and Hua Hin. Services will resume on Wednesday if conditions permit, the department said.
Ferries and speed boats from Surat Thani to Koh Samui, Koh Phangan and Koh Tao continue to operate for now, but the marine office was ordered by Surat Thani governor Wichawut Jinto on Sunday to halt all operations if the sea gets too rough.
While the southern region faces heavy rain, other parts of the country will see the mercury fall about 2°C before temperatures rise again on Wednesday and through to the weekend, according to the Meteorological Department.