Fine dust will likely plague most parts of South Korea until rain falls on Friday, authorities said Sunday, advising people to stay at home or to wear masks if they go outside.

Fine dust levels are expected to be “bad” across most of the country, including the greater Seoul area, Gangwon, Chungcheong, North Gyeongsang, Jeolla Provinces as well as inland cities including Daegu and surrounding areas, according to Korea Meteorological Administration.

As high levels of fine and yellow dust were issued across the country Saturday, weather authorities issued an ultrafine dust advisory for all regions except for the southernmost island of Jeju.

Fine dust levels have been higher over the past year compared to 2021. The daily average concentration of fine particulate matter smaller than 2.5 micrometers in diameter, also dubbed PM2.5, spiked to 86 micrograms per cubic meter, compared 2021’s yearly average of 18. Average levels of dust particles up to 10 micrometers in diameter, known as PM10, was 143 micrograms per cubic meter.

The Korea Meteorological Administration categorizes levels of fine dust between 81 and 150 micrograms as “bad” and more than 151 as “very bad.” An advisory is issued when hourly average concentrations of PM2.5 stay above 75 micrograms per cubic meter for over two hours.

Amid the spike in fine dust levels, Prime Minister Han Duck-soo last week ordered ministries and local authorities to take emergency measures aimed at tackling fine dust and reducing emissions as the country is coping with a severe deterioration in air quality.

“With the environment minister taking the lead, ministries and local government should thoroughly implement emergency reduction measures in line with the current high-concentration ultrafine dust measures,” Han said via a press release.

Under the measure, operating hours in places that emit a large amount of fine dust are to adjust their hours and operational rates, while construction sites are to change or adjust operation hours and use dust-proof coves.

The Seoul Metropolitan City stopped running its ice rink on Friday from 6:30 p.m. until Sunday. The city added that it would reopen the rink when emergency measures were lifted.

Meanwhile, authorities advised people to refrain from outdoor activities on such days and wear face masks if they have to go outside, as smog is blanketing most parts of the country.