Pedestrians walk through strong wind and rain near Gwanghwamun Square in central Seoul on Tuesday. (Yonhap) Early summer rain accompanied by gusty winds soaked much of the country Wednesday, with heavy rain advisories issued for parts of Greater Seoul, which includes Incheon and Gyeonggi Province.The Korea Meteorological Administration issued heavy rain advisories at around 4:30 p.m. for parts of Incheon, Gyeonggi Province, South Jeolla Province and South Gyeongsang Province. The alert is issued when rainfall is expected to exceed 60 millimeters over three hours or 110 millimeters over 12 hours.In response to the heavy rain, the Interior Ministry activated the Central Disaster and Safety Countermeasures Headquarters for the first time this year.The agency activated Level 1 of its three-tier emergency response system. Under the measure, related agencies such as local governments, fire authorities, police and the Korea Forest Service conduct real-time monitoring of weather conditions and potential damage nationwide.The response system expands in scale and manpower as weather alerts and damage levels intensify.The rain is expected to continue through Thursday morning before gradually clearing from the Seoul metropolitan area and inland Gangwon Province in the afternoon. In most other regions, the rain is forecast to taper off by Thursday night.Gangwon Province’s east coast and mountainous areas are expected to receive the heaviest rainfall over the two days, with accumulated precipitation forecast at 50-100 mm.Seoul and some inland areas of southern Gyeonggi Province are expected to see 20-60 mm of rain, while Gwangju and South Jeolla are forecast to receive around 10-50 mm.The rain is also expected to bring relief from the recent early summer heat. Morning lows Thursday are forecast to range from 14 to 19 degrees Celsius, with daytime highs expected between 17-24 C.