Overflows from the Chao Phraya River inundated three districts in Sing Buri and more than 100 households in Ang Thong on Wednesday.
Sing Buri Governor Surapol Sawangsak said three districts were flooded - Muang, In Buri and Phrom Buri. Water was up to a metre deep in some areas.
Mr Surapol said he had instructed local officials to make sure flood relief supplies get through to the people who need it. People were advised to closely watch for a rise in the floodwater.