Heavy rain responsible for floods across southern Thailand eased Wednesday, leaving residents to pick through damaged homes and ruined fields wrought by the 10-day deluge.

Record downpours have submerged vast swathes of Thailand's agricultural south since the beginning of the month, leaving at least 31 dead and affecting 1.1 million people.

The unseasonal weather has also struck popular beach destinations during Thailand's peak tourist period, sparking travel chaos with flights, railways and roads disrupted.

While much of the south remains under water, sunshine finally broke through raising hopes of an end to days of misery.

"There is no heavy downpour expected," Surangkana Jongsawat, the chief of Thailand's weather department, told AFP.

"The worst is over, now we have to wait for current flood waters to recede," she added.

Officials are now focused on delivering aid and rebuilding wrecked infrastructure.

Flash floods across the region have left considerable destruction in their wake, knocking down bridges and gouging hundreds of roads.

Muddy floodwaters have also inundated rubber and palm oil plantations and are likely to leave farmers with significant losses.

The total cost of the damage is still being calculated, officials told AFP.

Meanwhile, soldiers have been mobilised to deliver relief by boat and helicopter to swamped villages where the waters have reached roof-high levels in some areas.

"Our first priority is life," Charoen Watanasrimongkol, a Royal Thai Air Force captain organising airborne relief missions in Surat Thani province, told AFP.

"The current is strong so we need safety equipment to get people to hospital," he said, adding that authorities are focusing on reconstruction now that the rains have eased.