Children and teenagers attending a summer camp ride a banana boat to escape the heat at Gwangalli Beach in Busan on Friday. (Yonhap) After a week of record-breaking heat, South Korea entered the weekend with little respite from extreme weather.Temperatures are forecast to ease slightly, but stifling heat persists in the west while torrential rain batters parts of the east coast.Daytime highs Saturday are forecast to range from 26 C to 37 C. Temperatures will be slightly lower than Friday in Seoul, Gwangju and Daegu, reaching 35 C, while Daejeon is expected to reach 36 C and Changwon 37 C.In Seoul, daytime highs are forecast to fall to 33 C on Sunday and Monday. While that would bring a further easing of the heat, temperatures would remain high enough to warrant a heat advisory.The Korea Meteorological Administration said the extreme heat began to ease as the two high-pressure systems over the Korean Peninsula weakened. Clouds moving into the upper atmosphere also reduced the amount of direct sunlight reaching the ground.The easing came after South Korea experienced its hottest Ipchu on record Friday. Ipchu is one of the 24 seasonal markers of the traditional East Asian calendar and marks the beginning of autumn.Temperatures approached 40 C in several parts of the country Friday and reached 40 C in parts of Seoul, while the capital’s official high was 38 C, its highest of the year.Conditions were markedly different along the east coast, where a long, narrow band of rain clouds developed over coastal areas of Gangwon and parts of North Gyeongsang Province.Rain was also forecast to begin Saturday morning in the mountainous and mid-elevation areas of Jeju.The heavy rain developed as southeasterly winds from Typhoon Dolphin met northeasterly winds from a high-pressure system north of the peninsula, strengthening the flow of moist air from the east. The winds picked up additional moisture over the warm East Sea and were forced upward by the Taebaek Mountains, producing powerful rain clouds.Rain was falling in Gangneung at a rate of around 80 millimeters per hour Saturday morning. Heavy rain warnings are in effect for Gangneung and Donghae, while advisories have been issued for the rest of the Gangwon coast, including Samcheok and Yangyang, as well as Uljin in North Gyeongsang Province.The agency advised residents along the Gangwon coast and in nearby mountain areas, as well as on the northern coast of North Gyeongsang Province, to prepare for particularly intense rainfall.From Saturday through Monday, rainfall totals are forecast to reach 50 to 100 millimeters along the Gangwon coast and in its mountain areas. Northern coastal and northeastern mountainous areas of North Gyeongsang Province could receive 30 to 80 millimeters, while the province’s southern east coast is expected to receive 20 to 60 millimeters.Scattered showers are also forecast from Saturday afternoon through the evening in the Seoul metropolitan area, inland Gangwon Province, the Chungcheong and Jeolla regions and inland areas of the Gyeongsang provinces. Those areas could receive 5 to 40 millimeters.The rain and showers could be accompanied by gusty winds, thunder and lightning.Rain may briefly lower temperatures, but hot and humid conditions are expected to return once it stops.