Severe floods caused by monsoon rains have killed more than 30 people and displaced tens of thousands in Malaysia and southern Thailand, with both countries preparing shelters and evacuation plans in anticipation of more heavy rain.

With tens of thousands already displaced, both countries set up shelters in anticipation of further downpours.

At least 13 people died and tens of thousands evacuated in one of the worst floods in decades to batter southern Thailand and northern Malaysia.

In South Thailand, over 600,000 households have been affected by the relentless downpours and flash floods. The lives of 12 people have tragically been lost, and thousands of residents have been forced to evacuate their homes and seek refuge in temporary shelters.

The death toll from the worst floods in decades in southern Thailand and northern Malaysia climbed to at least 12 on Saturday, authorities said, as tens of thousands of people were evacuated due to rising water levels in the past three days.

The death toll from severe flooding in southern Thailand has risen to 25, with six provinces remaining inundated as water levels gradually receded, the Department of Disaster Prevention and Mitigation reported on Tuesday.

The floods also submerged large tracts of rice fields, causing millions of dollars in losses to farmers, officials said. The heavy downpour also damaged roads, houses and public facilities in Kelantan and other parts of Malaysia.

Malaysia and Thailand are facing a second wave of heavy rain and potential flooding this week, authorities said on Monday, even as some displaced residents were able to return home and the worst floods in decades began receding in some areas.