Extreme cold gripped South Korea on Thursday -- with a wind chill of minus 16 degrees Celsius in Seoul in the morning -- and it is forecast to reach its peak Friday, according to the country’s weather agency.

Thursday’s temperatures across the country hovered around minus 10 C in general, making it the coldest day of the year.

Runways at Jeju Airport were closed earlier in the day due to heavy snowfall of around 30 centimeters in some areas of the island. The closures led to 87 international and domestic flight cancellations and suspension of 29 flights until 11 a.m., according to the Korea Airports Corp.

In North Jeolla Province, police said nearly 500 traffic accidents had occurred on slippery roads since Tuesday, when heavy snow began falling, while 35 accidents were reported related to falling in the same province over two days.

The country’s power use soared in the morning amid a spike in heating demand, prompting Korea Power Exchange to order local companies to cut their power use in an effort to stabilize electricity reserves.

Lows dropped to minus 15 C in Chuncheon, minus 13 C in Seoul, minus 12 C in Daejeon, minus 7 C in Gwangju and minus 6 C in the southern port city of Busan.

Frigid conditions have gripped most parts of South Korea and are expected to last most of the week, while daytime temperatures remained around minus 7 C in the capital city, minus 5 C in Jeonju and minus 3 C in Daegu.

The coldest temperatures recorded this winter so far were on Dec. 12 and 13 last year, when morning lows dropped to minus 18.8 C before climbing to around 3 C in the daytime.

Wind-driven snow fell in South Chungcheong Province, the Jeolla provinces and Jeju, where extreme snowfall warnings were put in place.

Up to 30 centimeters of snow fell in Jeju, with up to 10 centimeters in some parts on the western coast of the peninsula, according to the Korea Meteorological Administration.

The weather agency forecast that the frigid weather would peak Friday and ease from next week.

The cold weather is related to a large area of high pressure in upper levels of the atmosphere near Alaska, driving the cold Arctic air pool to the country, the weather agency said.

Forecasters warned of frostbite and hypothermia risks, urging people to take necessary precautions when engaging in outside activities.

By Bak Se-hwan (sh@heraldcopr.com)