Residents cool off in a pool at Ttukseom Hangang Park on Saturday. (Yonhap) Average temperatures across most of South Korea are expected to be lower than last week's record-setting highs, while heavy rain is forecast for the eastern coast and Jeju Island.Heatwave warnings had been issued in 118 regions across the country as of 11:20 a.m. Sunday, including the Greater Seoul area and some regions in the Chungcheong, Jeolla, and Gyeongsang provinces. Heat wave advisories were issued across 82 regions.Daily highs in Seoul and Incheon are expected to reach 34 degrees Celsius. Temperatures in Daejeon, Cheongju in North Chungcheong Province, Jeonju and Gwangju were also projected to hit 34 C.Highs in Chuncheon, Gangwon Province, are expected to climb to 33 degrees, and southeastern cities of Daegu and Busan were both expected to reach highs of 32 degrees.Emergency heat wave warnings — the highest of a three-tiered system — have been lifted from all regions. Seoul recorded a high of 40.2 C in Nowon-gu on Friday, the first time a district in the capital surpassed 40 C since 2018.Meanwhile, temperatures in Gangneung, Gangwon Province, and Uljin-gu, North Gyeongsang Province, are only forecast to rise to 26 C and 27 degrees, respectively. This is largely due to heavy rain that fell upon the east coast area throughout the weekend, which is expected to continue at least until Sunday.Mountain regions and coastal areas in Gangwon will have between 30-80 milliliters of rain, with some areas expecting 100 mm. Busan and Ulsan can expect 20-50 mm of rain, while some regions in South Gyeongsang Province are expected to receive between 5-40 mm of rain.Jeju Island is expecting 20-70 mm of rain in mountainous regions, and 5-30 milliliters along its coastlines.Some regions in southern Gyeonggi Province and Gangwon Province are forecast to receive 5-40 mm in the afternoon, while forecasts expect up to 60 mm in North Chungcheong Province and Daegu.The drop in temperatures brought with the rainfall is expected to be temporary, with temperatures likely to climb again as high humidity levels persist.