The heat wave, cited as of the causes for Thursday’s widespread power outage, is to continue through Friday, according to the state weather agency.

The Korea Meteorological Administration said that as a high-pressure system has settled over the nation, the temperatures surged with those in some southern parts of the country reaching highs exceeding 33 degrees Celsius.

“As North Pacific high pressure continues to influence the country, hot air remained. On top of that, there were few clouds, which increased the amount of solar radiation,” a KMA official said, declining to be named.

“The hot weather will continue until Friday. Those who are elderly and weak need to refrain from outdoor activities and remain indoors where ventilation is good.”

The highest temperature recorded in a southeastern city of Daegu on Thursday was 34.2 degrees, the highest ever in the mid-September since the official temperature measure began. The highs in southern cities of Jinju, Suncheon and Gwangju were 32.8, 32.2, 33.3 degrees, respectively.

As of Thursday afternoon, heat wave watches were issued to a number of cities in South Jeolla Province, Gyeongsang Provinces and Daegu.

On Friday, the nation is forecast to see some clouds while some intermittent drizzling is expected in the northern parts of Gyeonggi and Gangwon provinces in the morning.

By Song Sang-ho (sshluck@heraldcorp.com)