Cold wave advisories have been issued for most inland regions as cold air traveling from the northwest caused temperatures to drastically drop.

The Korea Meteorological Administration(KMA) said on Friday that mercury levels in the central region and parts of North Gyeongsang and North Jeolla provinces are forecast to stay below zero during the day.

Advisories took effect in Daejeon, Daegu, Busan, Ulsan, Sejong, and inland areas of the Gangwon, Chungcheong, Jeolla and Gyeongsang regions. Advisories were issued Thursday night for Seoul and Gyeonggi Province.

A cold wave advisory is issued when morning lows are forecast to drop by ten degrees or more from the previous day to below three degrees Celsius, or predicted to fall below minus 12 degrees for two consecutive days or more.

Meanwhile, a heavy snowfall advisory is in place for parts of the southwestern Jeolla region, the southernmost Jeju Island, Ulleung Island and the easternmost Dokdo islets.