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South Korea extreme weather: Heat, floods, and cold waves

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2026-10-17 23:44 UTC → 2026-10-21 16:13 UTC · added ~~removed~~

The extreme weather patterns of summer 2026 in South Korea were characterized by intense heatwaves, localized heavy rainfall, and regional droughts. The Korea Meteorological Administration reported a national average temperature of 25.4 °C, the third highest since 1973. Temperatures exceeding 39 °C were recorded 42 times across 83 observation points, including a record 42.5 °C in Yangsan. In late August, despite the traditional onset of autumn, heatwave warnings and tropical night advisories persisted. High temperatures between 30 °C and 36 °C were common, accompanied by high humidity and localized thunderstorms. Heavy rainfall occurred throughout the month, including up to 80mm in the Yeongnam region and potential totals exceeding 250mm in parts of the Chungnam west coast due to a stationary front. The Korea Meteorological Administration warned of risks including landslides and sudden rises in river levels. By mid-September, weather patterns shifted toward significant temperature fluctuations. Throughout the month, daily temperature gaps of up to 15 °C were common in inland areas, accompanied by morning fog and coastal wind warnings. High waves of 4 to 5 meters were noted near Jeju and the East Sea, while dry conditions in Seoul and western Gyeonggi prompted fire prevention warnings. As of early October, a sharp seasonal transition occurred as cold air moved down from the north. ~~By October 5, a cold air mass from the northwest caused temperatures to drop further, with morning lows reaching as low as 3 °C, triggering the earliest cold wave advisory recorded since 2005.~~ Following a period of unseasonably warm weather—including a record October temperature in Seoul exceeding 30 °C—a new cold air mass caused temperatures to fall ~~sharply by October 14.~~ sharply. By October ~~12, morning lows below 10 °C led to frost or ice in mountainous and inland areas. On October~~ 17, heavy autumn rain with precipitation rates of 20 to 30 mm per hour was forecast to sweep across most of the country, accompanied by strong winds potentially exceeding 70 ~~km/h~~ km/h. By October 22, a significant cold snap was expected, with morning temperatures near 0 °C and ~~high waves.~~ wind gusts reaching up to 90 km/h in mountainous areas.

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