The death toll from flooding in southern Thailand has risen to 25, officials said on Tuesday, with days more heavy rain forecast.

Twelve provinces in southern Thailand have been hit by flooding since late November, affecting more than 410,000 people, the country's disaster agency said on its Facebook page.

The agency's announcement raises a previous death toll of nine reported on Saturday.

More than 22,000 people have been displaced from their homes due to flooding in Pattani, Narathiwat, Songkhla and Yala provinces, the Thai government's public relations department said.

Suwas Bin-Uma, a chicken farm owner in Songkhla, told state broadcaster Thai PBS that the floods had wiped out his entire flock of more than 10,000 chickens.

"I've lost at least three million baht (US$87,000)," he said.

The Thai weather agency on Tuesday warned of continued heavy rain until December 5.

The government has deployed rescue teams to assist affected residents and designated 50 million baht in flood relief for each province.

On Tuesday the Thai cabinet approved a 9,000 baht payment per family to support those affected.

In neighbouring Malaysia, south of the Thai border, disaster officials said on Tuesday that more than 94,000 people were yet to return to their homes after being evacuated to shelters due to the floods, with at least five people reported dead.

Maalaysian Prime Minister Anwar Ibrahim said five days of heavier-than-expected rain that battered the country's east coast last week was equal to the rainfall over the past six months, wreaking havoc in the northeastern state of Kelantan and neighbouring Terengganu.

The heavy downpours damaged roads and houses in Kelantan and other parts of Malaysia.

Rescue workers used boats to distribute food to victims trapped in their homes.

Anwar said it would cost the government an estimated 1 billion ringgit (US$224 million) to repair infrastructure damaged by the floods.

The rain eased over the weekend, but the Meteorological Department forecast heavy rains later on Tuesday.

Anwar said the government is bracing for another monsoon surge that is expected to hit on Sunday.

Scientists say climate change is causing more intense weather patterns that can make destructive floods more likely. (Agencies)