Some parts of Chiang Mai, Lamphun and Nakhon Ratchasima are already inundated.
A weather forecast station in Lamphun issued a warning yesterday urging residents living on mountain slopes and low-lying areas in some provinces in the upper and lower North and Northeast to prepare for floods.
Heavy rain on Monday caused a flood 30-40 centimetres deep at the Phimai Historical Park in Nakhon Ratchasima. Park officials rushed to pump water out of the stone building to prevent damage. Students at Phimai Damrong Wittayakom School nearby had to sweep up the debris and mud after a 50-centimetre deluge receded.
Meanwhile, more than 8,000 families were affected by floods in Mae Tha, Ban Thi, Pa Sang and Li districts of Lamphun, but waters had receded at press time.
In Chiang Mai province, heavy downpours on Monday night caused forest runoff to flow into canals in Fang district. Overflowing canals flooded roads to many villages and local agricultural areas. Water was around 50 centimetres deep.
Landslides also partly blocked some roads, including the link to Doi Angkhang and a road to Chai Prakan district.