The Meteorological Department of Thailand has issued an advisory that heavy rain was likely across the country particularly in the lower North, the Northeast, the Central as well as Bangkok and its vicinity.
Provinces along the eastern coast were expected to be hit by downpours.
The department said the rain would decrease in the Southern region but two metre waves could be expected in the Andaman Sea.
It said all ships should proceed with caution.
In Sakoln Nakhon, many advertisement boards were damaged by the continued heavy rain and strong winds, and local authorities are on high alert for possible large scale forest runoff from the Phu Phan Mountains.
Farmers in Phicht are worried after continued rain and runoff from Phitsanulok's Bang Krathum district have flooded their paddy fields. Floodwaters could not easily drain into the Yom and Phichit rivers because of dense weed and water hyacinth.
In Loei, the waters of the Loei River have risen to inundate riverside homes and the rain continues.
Meanwhile, the authorities in the southern province of Krabi have residents in its eight districts on high alert for possible forest runoff and landslide as the southwest monsoon prevails over the Andaman Sea.