Weather agency says the severity of the precipitation is only seen âonce in about 200 yearsâ.
Torrential rains hammered parts of South Koreaâs southern region, killing at least four people and causing travel chaos.
Heavy precipitation damaged property, roads, and infrastructure, with landslide warnings for at least 50 regions and more than 3,500 people displaced, the Ministry of the Interior and Safety said on Wednesday.
âI ask that people refrain from going to underground parking spaces, underpasses and streams during heavy rainfall,â Interior Minister Lee Sang-min said in a statement.
Weather department data showed three areas â Geumsan, Chupungnyeong, and Gunsan â experienced some of the heaviest hourly downpours on record.
âIt was a level of severity seen once in about 200 years,â an unnamed weather agency official told South Koreaâs Yonhap news agency.
On Wednesday, 131.7mm (5.4 inches) of rain fell in one hour, more than 10 percent of the areaâs average annual rainfall in Gunsan city.
South Korean broadcasters showed images of rivers overflowing and roads flooded, with people wading through waist-deep water in some areas. Four people died as a result of the torrential downpour.
The rain flooded an apartment building in Nonsan, with one man dying in a lift.
A house collapsed after being hit by a landslide in Seocheon, and rescuers found a man in his 70s inside. He was moved to a hospital but was later pronounced dead.
Another man in his 70s died after his car plunged into an overflowed stream, and a farmer in his 60s perished in Daegu after being sucked into a drainage system while inspecting his farm.
South Korea also experienced record-breaking rains and flooding in 2022, which killed at least 11 people.