The Emergency Medical Institute of Thailand reported that 26 more people had been killed in the floods, which began on October 10, most of them from drowning.
"Most of the victims died in their homes or were children playing near flood waters," said Chatree Charoencheewakul, the head of the institute. "It's likely that the toll could rise further as the flooding is still severe."
The authorities estimate that 4.2 million people have been affected, with homes submerged and farmland or cattle destroyed, mostly in central and eastern areas.
The floods spread to 38 of Thailand's 76 provinces although the waters have receded in 11 of those, officials said.
Nakhon Ratchasima, a large mountainous province about 250 kilometres (155 miles) northeast of Bangkok, is the worst affected with 18 deaths.
Nakhon Sawan, Lopburi and Ayutthaya just north of the capital have also been badly hit.
Bangkok has been on standby with thousands of sandbags and pumps as flood water from the north runs downstream and could coincide with high tide, but so far the capital has avoided major flooding.
Deccan Herald is on WhatsApp Channels | Join now for Breaking News & Editor's Picks