The Meteorological Department is warning of heavy rain in most regions of the country this week.
From Sunday to Tuesday the department expects heavy rain in the lower North, the Northeast, the Central Plain, the East and the South. Flash floods and runoff are possible in low-lying and steep areas.
The department attributed the incoming precipitation to the strong southwest monsoon and a low-pressure trough stretching from lower Vietnam via Thailand to Myanmar.
It advised small boats in the Gulf of Thailand and the Andaman Sea to remain ashore until Tuesday.
From Wednesday to Saturday the strong southwest monsoon would continue to cover the Andaman Sea, the southern mainland and the Gulf of Thailand. Consequently, there would be heavy rain in some areas of the Central Plain, the East and the South, the Meteorological Department predicted.
On Sunday morning, the department said, Typhoon Mawar was 695 kilometres east of Luzon in the Philippines and was moving westwards. The department expected the typhoon would head towards Taiwan and would not affect Thailand.