The Korea Meteorological Administration on Wednesday issued heat wave warnings and advisories in most parts of the country, with the temperature rising to 37.9 degrees Celsius in Gyeongju.
Seoul saw the mercury reaching as high as 33 C, while many other cities reported temperatures above 35 C.
Heat shimmers from the surface of a road in Yeouido, Seoul. (Yonhap)
The heat wave is likely to continue Thursday, the weather agency said.
Over the weekend, however, monsoon rains will hit the Korean Peninsula, cooling down the heat.
Heavy downpours are expected mostly in central regions.
The agency said Gyeonggi Province, Gangwon and North Chungcheong provinces are expected to see up to 150 millimeters of rain coupled with strong winds.
By Bak Se-hwan (sh@heraldcorp.com)