Phibun Mangsahan and Trakan Phuet Phon districts have been most affected so far, said Mr Serm.
Provincial and charity workers have been mobilised to help assist flood victims, he said.
Meanwhile, the flooding situation in the southern resort province of Krabi on the Andaman coast was similar to Ubon Ratchathani's following continued heavy downpours from yesterday.
Several areas including Plai Phraya district are now inundated while the Khlong Ya reservoir overflowed, entering two canals, causing the water level in the canals to rise sharply and flooding more than 10 homes and 100 rai of palm oil plantation.
House owners moved their valuables to higher ground while a number of roads are now covered with floodwater.
Motorists are forced to use alternative routes taking a longer time for each journey.
Meanwhile, a committee met at the Ministry of Agriculture and Cooperatives to discuss plans for coping with agricultural produce losses during the current monsoon season.
Participants also discussed plans to dispatch information and transport food during flood for the Department of Disaster Prevention and Mitigation to consider.
Storing food to cope with any agricultural losses disaster was also discussed.