Latest surveys showed that a total of 3,413 families in Nakhon Sawan were flooded in and some 45 roads and three dykes were damaged.
"We have declared Banphot Phisai district a disaster area," district chief Satawat Saenmuk said.
According to reports, the people were caught off guard by runoffs from the forests. Without enough time to move their belongings to higher ground, shop owners in Banphot Phisai's Somsiaw fresh market ended up having to watch their products being swept away.
Now, sandbags have been put up to protect the Banphot Phisai District Office and shop houses in the area.
In Angthong, floods have affected more than 300 residents, with waters more than one metre high in some areas.
Meanwhile, some 50 million cubic metres of water will be released from Lop Buri's Pasak Jolasid Dam every day, which means the Pasak River may overflow in some provinces like Saraburi, Ayutthaya and Pathum Thani.
"People along the river should start moving their belongings to higher ground," advised Ukrit Thavornkraikul, who is in charge of the dam's waterflow management. "The water has to be released because the dam has already reached its capacity."
Meanwhile, a threeyearold boy remains in coma after he slipped and fell on a flooded road in Prachin Buri on Sunday night.
"He was heading for his dad's car with his three siblings. Nobody saw him fall down," Pachok's mother Panadda Muangkhiaw said.
She said her husband found the boy under water after he noticed his sandals floating around. Pachok is being treated at the Abhaibhubejhr Hospital.
In Chiang Mai, floods also ravaged some parts of San Pa Tong district early yesterday and damaged more than 20 rai of rice fields. However, the waters had subsided as of press time.
"The situation has returned to normal," San Pa Thong senior city clerk Pattaraporn Laijud said.