The strongest cold wave so far this season has gripped the nation. 

According to the Korea Meteorological Administration(KMA), the daytime high in Seoul hit minus one-point-one degree Celsius on Friday, around seven degrees than the seasonal average in recent years.

The mercury in the capital is expected to drop to as low as minus 11 degrees on Saturday and Sunday, compared to Friday's low of minus nine-point-one degrees, and remain below zero throughout the weekend. 

In light of conditions, the weather agency said it will issue a cold wave advisory for Seoul for the second time this winter, following the one issued on Tuesday. The advisory will take effect from 11 p.m. Friday and extend to some surrounding areas in Gyeonggi Province.

The KMA also said it will issue the season’s first cold wave warning for parts of Gyeonggi and Gangwon provinces.

A cold wave warning is issued when morning lows plunge more than 15 degrees Celsius from the previous day to under three degrees and are at least three degrees lower than the annual average or when morning lows remain below minus 15 degrees for more than two days. 

A cold wave advisory is issued when morning lows dip more than ten degrees from the previous day to under three degrees and are at least three degrees lower than the average or when morning lows continue to stand at minus 12 degrees or lower for more than two days.