The nation will see gradually overcast skies on Thursday, with rain or snow expected in most regions from the afternoon.
According to the Korea Meteorological Administration, rainfall will be light at less than five millimeters, but snowfall could be substantial, reaching up to eight centimeters.
Between three and eight centimeters of snow is forecast for northeastern Gyeonggi Province and the northern inland and mountainous regions of Gangwon Province, while one to five centimeters is expected elsewhere.
Seoul is also likely to see its first snowfall of the season.
Much of the central region is under a cold wave advisory, with morning lows dropping to around minus ten degrees Celsius, making it colder than the previous day.
Daytime temparatures will be slightly higher than Wednesday, but they will still be low, reaching two degrees in Seoul, four in Daejeon, and six in Gwangju and Daegu.
The cold snap is expected to ease over the weekend.