South Korea’s Summer of Drenched Disasters: Rainfall Hits Record Levels!

As South Korea faces its most severe summer rainfall season in decades, new data shows that dangerous downpours are no longer an anomaly.

The Korea Meteorological Administration (KMA) reported that during the summer of 2024, there were 31 instances where rainfall exceeded 80 millimeters in a single hour. This figure far exceeds the mere 8 such events recorded in 2015, marking an almost fourfold increase.

Although the annual totals have fluctuated over the past decade, the KMA notes a clear upward trend. The agency also highlights that heavy rainfall now extends beyond the traditional monsoon season, which typically ends in August. These intense bursts, often surpassing 50 millimeters per hour, have become more frequent.

The KMA defines “extreme rainfall” as precipitation of at least 50 millimeters in one hour, 90 millimeters or more over three hours, or a single-hour downpour of 72 millimeters or more.

Last week shattered these criteria. Between July 17 and 20, at least 10 regions experienced daily rainfall that the KMA says occurs only once every two centuries. Ongjin County in Incheon and Pocheon in Gyeonggi Province witnessed rare one-hour extreme events. Meanwhile, Seosan in South Chungcheong Province and Gwangju set new national daily records, each receiving over 426 millimeters of rain.

KMA meteorologists attribute this phenomenon to the collision of contrasting air masses. Unusually far to the south, dry and cold air lingered over the Korean Peninsula, colliding with warm, moisture-laden air surging in from the Pacific. This clash created a stagnant, volatile zone where storm clouds repeatedly formed over the same areas.

However, this weather pattern is now shifting. The Pacific high-pressure system is expanding, trapping hot and humid air and setting the stage for prolonged heat waves.