The cold snap will abate on Thursday but the air will be murky with toxic haze across the country.
The concentration of fine particles will likely stay at the mildly dangerous level of 81-120 ㎍/㎥ on average in most parts of the country except Jeju on Thursday as toxic haze is blown into the Korean Peninsula from Tianjin and other parts of China, the National Institute of Environmental Research said on Wednesday.
It advised old or weak people and patients with respiratory diseases to avoid staying outdoors for a long time.
The toxic haze will travel on the northwesterly wind, starting in the Seoul metropolitan area and then spreading south.
But temperatures are rising with the morning low in Seoul at -4 degrees Celsius, three to four degrees higher than the previous morning, and the day's high at 4 degrees Celsius, the Korea Meteorological Administration forecast.
In some southern cities like Busan and Daegu temperatures will rise to 7 to 8 degrees.