Seoul was battered by heavy downpours and strong gusts on Sunday, 18 October 2026, triggering urban flooding, traffic disruptions, and safety hazards across South Korea's capital. City fire authorities logged 129 emergency calls by 5:00 pm local time, as inundated roads, fallen trees, and clogged drainage systems stretched emergency services.

Rainfall Intensity and Peak Zones

Gangbuk Ward in northern Seoul recorded a peak hourly rainfall of 53.5 millimetres — the highest hourly intensity logged anywhere in the country during the storm. Cumulative rainfall in the ward reached 65 mm by 5:00 pm, while the southern Songpa District recorded the city's lowest accumulation at 20 mm. Heavy rain advisories covering the northeastern, northwestern, and southwestern districts were lifted at 3:30 pm, though scattered showers continued through the afternoon.

Emergency Response and Alerts

Seoul activated Level 1 emergency response protocols at 2:40 pm and partially operated 12 rainwater pumping stations to clear flooded roads. An emergency text alert was sent to residents at 3:16 pm, urging them to avoid low-lying and high-risk areas. Of the 129 emergency calls received, 47 were for drainage assistance, 21 reported fallen trees, and 60 were safety inspection requests for public facilities. City officials also restricted access to 16 major urban streams as water levels rose.

Traffic Disruptions and Street-Level Impact

Roads beneath the Jeungsan Bridge in Seodaemun Ward were completely blocked around 3:04 pm due to flooding. Weather warnings were issued for major highways, advising drivers to exercise caution on wet roads and against high winds. A tree fell onto a busy road in Gangnam Ward in southern Seoul, obstructing both traffic and pedestrians. In Eunpyeong Ward in northwestern Seoul, water levels in some low-lying areas rose above the knees. Municipal officials noted that fallen leaves swept by gale-force winds had clogged drainage systems, compounding the flooding. Some shop owners were seen manually clearing leaf-blocked catch basins to speed up drainage.

Events Cancelled, Damage Ongoing

The storm forced the cancellation of major outdoor events, including the Grand Mint Festival scheduled at Olympic Park in Songpa. A Seoul official said damage reports were still coming in even as rainfall appeared to ease. 'Although the rain appears to be letting up, reports of damage continue to come in,' the official said. 'Our primary focus is on rapidly resolving pending safety reports and preventing secondary accidents in close cooperation with district offices.'

Authorities have urged residents to remain cautious as secondary hazards — including waterlogged roads and weakened infrastructure — persist in the storm's aftermath.