A heat wave advisory has been issued in Seoul for the first time this year.

The Korea Meteorological Administration(KMA) issued the advisory at 10 a.m. Friday.

Aside from the capital city, the advisory also covered Gyeonggi Province, including the cities of Gunpo, Seongnam, Gwangmyeong, Yangpyeong, Icheon, Hanam, Suwon, Goyang, Dongducheon, Bucheon and Gwacheon.

A heat wave advisory is issued when the day's high surges to 33 degrees Celsius or higher for two consecutive days. A heat wave warning is issued when the daytime high reaches 35 degrees or higher for two straight days.

A KMA official advised people to remain indoors on Friday and stay hydrated.

Screening the sunlight and staying in ventilated areas were also recommended as ways of avoiding the heat.