More than 20 centimeters of snow blanketed parts of the capital city overnight, prompting heavy snow alerts in the greater Seoul area and Gangwon Province, the state weather agency said Wednesday.

A heavy snow warning was issued in parts of northeastern Seoul, including Nowon, Seongbuk, and Dobong districts, shortly after the city experienced its first snow of the season, according to the Korea Meteorological Administration and the Seoul metropolitan government.

An advisory is issued when snowfall is expected to reach 5 cm or more within 24 hours, and a warning is issued when it exceeds 20 cm within the same period.

Much of the country, including the greater Seoul area, parts of North Chungcheong Province, eastern North Jeolla Province, and some mountainous regions of North Gyeongsang Province, is expected to see 1 to 3 cm of snow per hour in the morning, with snowfall continuing into the night in Gangwon Province.

The interior ministry activated Level 1 operations of the Central Disaster and Safety Countermeasures Headquarters and raised the heavy snow warning to "caution."

The disaster control tower warned of traffic congestion during morning and evening rush hours, pile-up accidents on icy roads, and safety risks for pedestrians due to the heavy snow.

Starting at 7 a.m., the Seoul metropolitan government began snow removal operations in cooperation with district governments and relevant agencies.

It also restricted access to roads leading to Mount Inwang and Mount Bugak, as well as roads in Samcheong-dong, near Gyeongbok Palace, and Waryong Park.

Interior Minister Lee Sang-min instructed officials to conduct thorough snow removal operations. (Yonhap)