The tourist hub of Hat Yai has been particularly affected, stranding people in homes and hotels and claiming at least 13 lives across four provinces, AFP reported.
Thailand’s government declared a state of emergency in southern Songkhla province on Tuesday as the meteorological department forecast more rain and possible flash floods this week.
Local television footage showed rescuers in Hat Yai evacuating people via boats, jet skis and military trucks through high floodwaters.
Some residents used inflatable children’s swimming pools to float their kids to safety.
“I was stranded for four days,” a woman wearing a rain poncho and holding her baby under an umbrella told local TV station TNN.
“I decided to leave because I have an infant and I am afraid more water will come,” she added.
The woman, her child and her bedridden mother were eventually evacuated by boat.
More than 1,200 people have been evacuated from their homes in Songkhla since Thursday, according to the province’s public relations department.
Prime Minister Anutin Charnvirakul told reporters that more boats and trucks would be deployed to aid in evacuations.
Thailand regularly records heavy rainfall from June to September, but experts say human-induced climate change has intensified extreme weather patterns.