Seoul: Heavier-than-expected downpours have been forecasted in South Korea's southern provinces, with the southwestern county of Muan experiencing a near-record 142.1 millimeters of rainfall in just one hour on Sunday, according to the state weather agency.

According to Yonhap News Agency, the rainfall in Muan between 7:10 and 8:10 p.m. on Sunday accounted for approximately 11 percent of the county's annual average rainfall. The country's record for hourlong precipitation is 145 mm, set in July 1998. As of 9 p.m., hourly rainfall of 30 to 80 mm was reported in southern and western provinces, as per the Korea Meteorological Administration (KMA).

The KMA has forecast that the rainfall will persist through Tuesday morning, with precipitation expected to reach between 100 to 200 mm, and up to 250 mm in areas like Gwangju and South Jeolla Province, excluding the southern coastal regions. Most parts of the country are expected to receive 30 to 80 mm of rain per hour through Monday morning.

In response to the heavy rains, the interior ministry activated the Level 1 operation of the Central Disaster and Safety Countermeasures Headquarters for the western Jeolla and Chungcheong provinces as of 6 p.m. Interior Minister Yun Ho-jung emphasized the importance of preventing damage to accommodations near streams and creeks, stressing the need for thorough monitoring and swift evacuation.

The agricultural ministry has also put a 24-hour emergency response system in place through Tuesday, coordinating with local governments and relevant agencies. On-site response efforts have been bolstered in areas prone to floods and landslides. South Gyeongsang Province raised its emergency response posture to Level 1 earlier in the day following a preliminary heavy rain advisory.

Heavy rainfall is anticipated to focus on southern coastal areas and around Mount Jiri, which previously suffered significant damage during torrential rains in July. This raises concerns over potential additional damage. North Jeolla Province also activated a Level 1 emergency response system after a preliminary heavy rain advisory was issued for 10 cities and counties within the province.

Local government officials have urged residents to frequently monitor weather updates, avoid unnecessary outings, and steer clear of risky areas such as riverside trails, slopes, and low-lying roads. Visitors at beaches and campgrounds have been advised to exercise caution and evacuate in advance if necessary.

Last month, South Korea experienced heavy rains and landslides, which resulted in 23 fatalities and left five others unaccounted for across the country. As the rain continues, heat wave advisories are expected to be gradually lifted or eased, with daytime high temperatures ranging between 29 and 34 degrees Celsius, according to the KMA.