An ultrafine dust advisory has been issued for Seoul and Incheon on Friday.

According to the Korea Meteorological Administration, the concentration of ultrafine dust is also high in the central and North Jeolla regions, while Gyeonggi Province recorded a concentration of 72 micrograms and 64 micrograms for South Chungcheong Province.

The levels will be high in most areas across the country except the Yeongdong region in Gangwon Province as well as South Gyeongsang Province.

Meanwhile, the cold snap is forecast to return Saturday.

The morning temperature in Seoul tomorrow will be at minus four degrees Celsius, while the temperature will drop further to minus six degrees on Sunday morning and remain below zero during the day.