A child plays with water at Gwanghwamun Square in Seoul, June 23. Korea Times photo by Shim Hyun-chul The state weather agency issued a heat wave advisory for all of Seoul on Monday, the first such alert for the capital this year.The advisory took effect as of 11 a.m., the Korea Meteorological Administration said. Advisories will also take effect in other parts of the capital area and the central cities of Gongju, Cheongju and Sejong.A heat wave advisory is issued when the maximum apparent temperature is expected to remain at or above 33 C for two or more consecutive days.Previously, advisories were issued for the southeastern and southwestern regions of Seoul on June 18.