The streets of Gangnam district were turned into a river due to the heavy rains. There were at least seven deaths and six missing.
Emergency crews worked through the night to clean up the mess. There were concerns that there would be more damage as the rain was predicted to continue.
Around 80 roads and dozens of riverside parking lots remained closed due to safety concerns despite the subway services being back to normal.
The president called for public employers and private companies to adjust their working hours and urged them to restore damaged facilities and evacuate people in danger areas. Moon Hong-sik said the military was prepared to help with recovery efforts if asked.
The rain intensified over the course of the night. The Ministry of the Interior and Safety said that hundreds of people were forced to leave their homes because of the damage.
People were seen wading through thigh-high waters in streets near the Gangnam subway station, one of the most bustling business and leisure districts in the city. Water cascaded down the stairs of the Isu subway station, causing commuters to evacuate. There is a soccer field in the city of Seongnam.
Rescue workers were unable to reach three people who called for help before they drowned in a basement home. A public worker died while clearing up fallen trees and another woman drowned at her home. The official from the district office said it wasn't clear if the water was electric because of a damaged power source or equipment.
The bodies of two people were found in the rubble of a collapsed bus station.
Four people went missing in the southern part of the city, which is also home to the private residence of Yoon, who spent hours on the phone receiving briefings and issuing instructions overnight as the rain flooded some streets near his high-rise apartment complex.
We need to maintain our sense of alert and respond with all-out effort as the rain is expected to continue for days. He directed officials to look out for areas that are vulnerable to flooding and to look out for roads that are already damaged.
The country's weather agency maintained a heavy rain warning on Tuesday and said the precipitation could reach up to 10 centimeters an hour in some areas. More rain is expected in the capital region through Thursday.
There was more than 17 inches of rain in the hardest-hit district. At one point Monday night, the per-hour precipitation in that area exceeded 14 centimeters, which was the highest since 1942.
Heavy rain warnings were issued for the south and west of North Korea. The Rodong Sinmun called for measures to protect farmland and prevent flooding on the Taedong river, which flows through the capital of the country.