Gangneung recorded a nighttime minimum temperature of 30.2 °C this week, marking the first "ultra-tropical night" observed in South Korea this year [1].
This extreme temperature spike indicates an intensifying heatwave that prevents the environment from cooling down overnight. Such conditions increase the risk of heat-related illnesses and place significant strain on the national power grid as cooling demands surge.
The phenomenon, known as "cho-yeoldaya," occurs when the lowest temperature during the night remains above 30 °C [1]. A YTN reporter said the nighttime low of 30.2 °C in Gangneung, located in Gangwon Province, was the first instance of this specific extreme heat event for the current year [1].
The heat is not isolated to the east coast. In Seoul, the city has endured 10 consecutive tropical nights [1]. This persistence of high overnight temperatures is part of a broader national trend, as nationwide average tropical night days have reached nine out of 30, which is a record high [1].
Weather officials warn that the oppressive heat will continue during the day. Daytime temperatures across the nation are expected to reach up to 40 °C [1]. A YTN anchor said the "steaming heat" is persisting across the country while the ultra-tropical night appeared in Gangwon Province [2].
Residents are being urged to take precautions against the extreme heat. The combination of daytime peaks and nighttime lows that fail to drop below 30 °C creates a cycle of heat stress that leaves the human body with little time to recover.
“Gangneung recorded a nighttime minimum temperature of 30.2 °C, marking the first 'ultra-tropical night' observed in South Korea this year.”
The emergence of 'ultra-tropical nights' signals a shift toward more extreme summer weather patterns in South Korea. When nighttime temperatures fail to drop, the cumulative physiological stress on the population increases, potentially leading to higher mortality rates among vulnerable groups and increased energy consumption for air conditioning.
