Nearly one million people have now been affected by widespread flooding across Myanmar since June, officials say.
The government says up to 100 people have died and 1.2 million acres of rice fields have been destroyed.
Though schools in some areas have reopened, fresh warnings have been issued to people living in the Irrawaddy Delta region.
Myanmar (also known as Burma) always sees flooding in the monsoon season but this is some of the worst in decades.
The floods were made worse by Cyclone Komen, which ploughed through the country last week, causing extensive damage to the deprived Rakhine state.
All but two of the 14 states have been affected - most of the deaths have been in Rakhine.
Patrick Fuller, of the International Committee of the Red Cross in Yangon, said the situation in many areas remained desperate.
People were "returning home to nothing", with their homes and belongings buried in mud, he told the BBC.
The New Light of Myanmar state-run newspaper said water levels in the Irrawaddy and Ngawun rivers had fallen slightly on Sunday, but remained at risk of bursting their banks.
Residents in low-lying delta areas have been urged to move to higher ground.