Another moderate high pressure over southern China is expected to cover the Northeast of Thailand and the South China Sea by Monday, The Meteorological Department announced on Sunday.
As a result, a cold spell and strong winds are expected in the Northeast and temperatures could drop by between two and four degrees Celsius.
Meanwhile, a northeast monsoon prevails over the Gulf and the South of Thailand is expected to strengthen. Strong wind and waves 2-3 metres high are likely from Surat Thani downward.
The department warned that all people should beware of inshore surf.
All vessels should proceed with caution and small boats keep ashore during Feb 15-18, it said.