A reservoir in Gyeongju, North Gyeongsang Province, has been reduced to small pools amid an ongoing drought and heatwave, as the city recorded 40.2 degrees Celsius on Sunday. (Yonhap) South Korea’s record-breaking heat wave is expected to persist, raising the risk of more heat-related illnesses as weather authorities monitor a powerful typhoon moving across the western Pacific.Yangsan, South Gyeongsang Province, recorded 42.5 degrees Celsius as of 1:26 p.m. Sunday, the highest temperature ever measured anywhere in South Korea, according to the Korea Meteorological Administration. Heat wave warnings were likely to remain in effect for several regions throughout the week.However, the path of Typhoon Dolphin has added uncertainty to weather outlooks. Depending on its eventual course, the storm could draw more hot, humid air toward the Korean Peninsula or bring winds, clouds and rain that provide temporary respite. Seoul's weather forecast from Sunday to Aug. 11 (KMA) Heat-related illnesses expected to riseA total of 1,781 people were treated for heat-related illnesses nationwide between May 15 and Friday, according to the Korea Disease Control and Prevention Agency. Thirteen deaths were suspected of being linked to the heat.The number of patients remains below the roughly 2,800 recorded during the same period in 2025, but health authorities expect the toll to rise as extreme temperatures continue.In a forecast released Sunday, the KDCA projected at least 19 heat-related illness cases in each of six of the country’s 17 cities and provinces on Monday. The remaining regions, except Jeju Island, were expected to see between six and 18 cases.The most severe heat has been concentrated in the southeast. Yangsan on Wednesday became the first location in Korea to exceed 40 C in 2025 and went on to break the national temperature record for three consecutive days from Friday through Sunday.Temperatures in neighboring Busan and Ulsan have also approached 40 C. About one-fifth of all heat-related illness cases nationwide have been reported in Busan, Ulsan, Daegu and North and South Gyeongsang provinces.Seoul and other western areas have been under heat wave warnings. Easterly winds are expected to push hotter air inland Monday, when the capital is forecast to reach 37 C.“Maximum apparent temperatures will remain around 35 degrees across most parts of the country for the time being,” a KMA official said. “People should drink plenty of water, avoid outdoor activities whenever possible and pay close attention to their health to prevent heat-related illnesses.” Forecast track of Typhoon Dolphin (translated from Korean data provided by the KMA; KMA, ChatGPT) Typhoon track may alter heat waveWeather authorities are also closely watching Typhoon Dolphin, whose path could determine whether the heat wave intensifies or begins to ease.As of Sunday midday, the typhoon had a central pressure of 930 hectopascals and maximum sustained winds of 50 meters per second. It was forecast to move toward the East China Sea by Friday.According to the KMA, the storm’s eventual course will depend on how it interacts with surrounding pressure systems after approaching Okinawa, Japan.Should the typhoon move toward eastern China, moisture circulating along its outer edge could flow into the Korean Peninsula, increasing humidity and potentially worsening the heat wave and tropical nights.A track closer to waters south of the peninsula could bring stronger winds, greater cloud cover and rain, temporarily easing the heat while posing separate risks from heavy rainfall and high winds.The KMA said the typhoon was expected to weaken somewhat near Okinawa but could still carry maximum sustained winds of about 45 meters per second.“Small changes in the pressure systems surrounding the Korean Peninsula, including the path of Typhoon Dolphin and the position of the North Pacific High, could significantly affect temperatures and rainfall,” a KMA official said.“Early in the week, it should become clearer whether the typhoon will directly affect Korea and which areas would face the greatest risks.”