Sweltering heat gripped the entire country on Thursday, with the temperature in Ulsan soaring to 38.8 degrees Celsius, according to the weather bureau in the city.
That was the highest official temperature in the 81 years since weather data were first compiled for the city.
According to the Korea Meteorological Administration, the mercury also crept up beyond 37 degrees in Uljin (37.8 degrees), Milyang (37.6 degrees), Gyeongju (37.4 degrees), and Pohang (37.2 degrees), and to some 35 degrees in Jeonju (36.9 degrees), Daegu (36.8 degrees), Gangneung (35.9 degrees), and Daejeon (34.1 degrees).
In Seoul, the average daily temperature reached 32.8 degrees.
The heat wave has reduced the number of tourists to beaches or valleys. Some 1,500 to 1,600 people visited Mangyangjeong Beach in Uljin, North Gyeongsang Province on a daily average until last week, but that dwindled to a mere 850 on Thursday.
"Many people are staying indoors because of the high temperatures at midday," a staffer at the beach service center said. "Many vacationers come often to our air-conditioned office to escape the heat."
There have been fatalities. A 54-year-old man collapsed at a building site in North Chungcheong Province on Wednesday afternoon. He was taken to a hospital, but died the following day. Some 2,500 chickens died in the suffocating heat in Haenam, South Jeolla Province that day.
The summer heat wave is here to stay until mid-August, with the mercury expected to soar past 30 degrees across the country on Saturday and Sunday as well.