25.08.03.Today News : 140.8mm Torrential Rain Hits Muan in Just One Hour

140.8mm Torrential Rain Hits Muan in Just One Hour

• Muan Airport records second-highest hourly rainfall since 1973 as heavy rain clouds stall over Honam

A record-breaking downpour hit Muan County in South Jeolla Province on the evening of July 3, with 140.8mm of rain falling in just one hour. The extreme weather, caused by a stagnant band of rain clouds, is expected to bring even more rainfall across the Honam region in the coming days.

There's a lot of rain across the country, and you need to be careful.

According to the Korea Meteorological Administration (KMA), from 7 p.m. to 8 p.m. on July 3, the automatic weather station (AWS) at Muan Airport in Mangun-myeon recorded 140.8mm of rainfall. This marks the second-highest one-hour rainfall in South Korea since the expansion of the national observation network in 1973, following 145.0mm in Juam-myeon, Suncheon in 1998. When including AWS data, the highest recorded is 146.0mm on July 10, 2023, in Eocheongdo, Gunsan.

Muan typically receives about 1,290mm of rain annually, making the single-hour deluge equivalent to 11% of its average yearly precipitation—a true “rain bomb.”

The heavy rain was not limited to Muan. Torrential rainfall exceeding 100mm per hour was reported in other areas including South Chungcheong, Honam, and South Gyeongsang Provinces. The KMA warned that a strongly developed rain cloud band would remain stalled over the Honam region, continuing to pour large amounts of rain.

As of 7:50 p.m. on July 3, the KMA forecasted 100–200mm of rainfall for Gwangju and South Jeolla by the morning of July 5, with some areas expected to exceed 250mm. South coastal Jeolla is projected to receive 80–150mm, with local maxima of over 200mm—figures higher than the earlier 5 p.m. forecast.

Beyond South Jeolla, other areas are also expected to experience substantial rainfall. Forecasts include: 80–150mm for Busan, Ulsan, and South Gyeongsang (up to 250mm near the southern coast and Mt. Jiri); 50–100mm for Seoul, Incheon, the Capital Area, and Chungcheong (with maxima of 180mm in South Chungcheong and North Jeolla); and 30–80mm for Gangwon, Daegu, North Gyeongsang, and parts of Jeju Island.

The KMA stressed that the slow-moving storm system could bring repeated downpours through July 5, urging the public to remain alert for possible landslides, flash floods, and property damage.

One-line summary : A record-breaking 140.8mm of rain fell in one hour in Muan, South Jeolla, with extreme rainfall expected to continue across the Honam region and beyond.