Central South Korea on alert for overnight deluge, landslide danger

South Korea’s emergency authorities have issued a nationwide alert ahead of what could be one of the most intense rain events of this summer monsoon season.

As of 3 p.m. Wednesday, the Central Disaster and Safety Countermeasures Headquarters, operated by the Ministry of the Interior and Safety, entered Level 1 activation. This initial phase is launched when localized damage is expected and allows national agencies to begin coordinated emergency preparations.

The Korea Meteorological Administration forecasts 150 to 200 millimeters of rain from Wednesday evening through Thursday across Seoul, the surrounding Gyeonggi Province, the central Chungcheong region, Gangwon Province and parts of the southwest. Such a volume of rain can overwhelm drainage systems, flood low-lying roads and trigger landslides in hilly terrain.

Additional heavy downpours are expected in southern regions and Jeju Island later this week.

Authorities have flagged Wednesday night and early Thursday as the highest-risk period. A spokesperson for the disaster headquarters said all relevant agencies have been told to stay fully mobilized and to issue disaster alerts across all available platforms, including mobile warnings and local broadcasts.

Residents are urged to stay indoors during the heaviest rainfall and to avoid flood-prone areas.

In a related move, the Korea Forest Service raised its national landslide alert to the "Caution" level at 2:30 p.m. This alert now covers every major region, including Seoul, Incheon, Busan, Daegu, Daejeon and Jeju Island.

South Korea's steep terrain and high population density make urban areas particularly vulnerable during monsoon rains, especially in neighborhoods near hillsides or with outdated drainage systems.

Acting Interior Minister Kim Min-jae, who also leads the disaster headquarters response, warned that with rainfall continuing from the weekend, the risk of landslides and flash floods is high. He called on the public to monitor updates and stay away from riverbanks, underground spaces and steep slopes.