Summer weather smashed records, driven by ocean temperatures heating up.

South Korea Experiences Record-Breaking Summer Heatwave

South Korea has faced an unusually hot summer this year, with temperatures soaring to record highs and rainfall levels dropping significantly. According to the Korea Meteorological Administration (KMA), the country experienced an average of 28.1 heatwave days and 15.5 tropical nights, both ranking among the top five in weather records.

The scorching conditions began in late June, unlike previous years when they set in after the monsoon season ended in late July. The early heat was attributed to the unusually fast expansion of the North Pacific high-pressure system, which was caused by warm sea surface temperatures around the Korean Peninsula and stronger convection in the western Pacific.

The responsibility for research and prevention of prolonged and extreme summer heat in South Korea primarily lies with South Korean government agencies such as the KMA and related public health and environmental bodies. These institutions conduct climate research, heatwave monitoring, and implement prevention measures to protect public health.

Other cities, including Busan, Incheon, Gangneung, Sokcho, Mokpo, and Cheongju, also recorded the highest number of tropical nights in history. Gangneung, in particular, has been hit with a flash drought since July, caused by scarce rainfall and record-breaking heat waves that quickly evaporate water sources.

As a result, South Korea's summer rainfall totaled 619.7 millimeters, around 85 percent of the seasonal average. Between July 16 and 20, 200 to 700 mm of rain fell nationwide. However, extreme downpours concentrated in the southern parts of the country, triggering landslides and floods in heavily hit regions, including the South Jeolla and South Gyeongsang provinces.

The average daily high temperatures reached a record 30.7 C, while the average daily lows were the second highest on record at 21.5 C. Seoul had a record 46 tropical nights, marking a 3.5-fold increase compared to the city's historical average. Tropical nights arrived earlier than usual, with Daejeon and Gwangju recording their earliest tropical nights on June 19.

The Tibetan high-pressure system and the North Pacific high-pressure system overlapped above the Korean Peninsula from mid-to-late August, creating a double high-pressure system. This year's summer in South Korea was the hottest since 1973, with an average temperature of 25.7 degrees Celsius.

The seas around the Korean Peninsula saw their average temperatures soar to 23.8 C, the second-highest recorded in the past decade. As of Thursday morning, water reserve rates at Obong Reservoir, the largest source of water for Gangneung, were recorded at 13.7 percent - its lowest on record.

The KMA added that Korea may face "longer and harsher summers in the coming years," with higher chances of more intense swings between droughts and downpours. The institutions are working diligently to monitor the situation and implement prevention measures to protect public health and mitigate the impacts of extreme weather events.