The cold snap gripped the country on Sunday, pushing down the morning low to minus 10.3 degrees Celsius in Seoul.
Morning lows on Sunday went down to minus 17.1 in Cheolwon - the lowest in the country - minus 14.4 in Chunchon, minus 10 in Daejon and minus 6.8 in Busan.
The Korea Meteorological Administration said Sunday that the temperature would drop further Monday, with the morning low expected to plunge to minus 11 degrees Celcius in Seoul.
The weather center said the cold temperatures will gradually subside beginning Thursday.
Despite the cold weather, major ski resorts, mountains and theme parks across the nations were crowed with holidaymakers.
Some 10000 people visited Muju Ski Resort in North Jolla Province to enjoy winter sports and