The state weather agency on Friday issued a heat wave warning for Seoul for the first time this year, advising people to stay indoors.
With the mercury soaring well above 30 degrees Celsius, a heat wave advisory that had been in place in the nation's capital was upgraded to a heat wave warning as of 12 p.m., the Korea Meteorological Administration (KMA) said.
The weather agency said it also posted heat wave warnings for cities north of the capital.