Japan and South Korea record hottest summers in history, with scientists warning that human-driven climate change is fueling extreme weather across East Asia. Both nations endured record-breaking average summer temperatures in 2025, surpassing all previous records.
Japan’s Scorching Summer
The Japan Meteorological Agency (JMA) confirmed that the country’s average summer temperature was 2.36°C above the 1991–2020 baseline. This marks the hottest summer since record-keeping began in 1898. Out of 153 weather stations nationwide, 123 reported record-breaking summer averages.
Japan also logged a record 9,385 “extremely hot days” across automated stations. The city of Isesaki set a new national record of 41.8°C, breaking the highest temperature ever recorded in Japan twice in the same day.
The JMA has urged residents to take precautions against heatstroke as severe heat conditions are forecast to persist, particularly in eastern and western regions over the coming weeks.
South Korea’s Record Heatwave
South Korea also experienced its hottest summer since data collection began in 1973. The Korea Meteorological Administration reported an average summer temperature of 25.7°C, narrowly surpassing last year’s record of 25.6°C. This back-to-back pattern highlights the intensifying trend of rising heat across the peninsula.
Authorities warned that prolonged exposure to such extreme weather conditions could strain public health systems and impact vulnerable communities, particularly the elderly and outdoor workers.
Climate Change Intensifies Extreme Weather
Scientists point to climate change as the driving factor behind the relentless heat. The World Meteorological Organization (WMO) highlighted Asia as one of the regions warming nearly twice as fast as the global average. The UN agency’s June climate report revealed that Asia’s average land temperature in 2024 was 1.04°C higher than the 1991–2020 norm, making it among the hottest years on record.
Heatwaves across Asia are not only threatening lives but also causing economic disruptions, damaging crops, and straining energy systems. The frequency and intensity of these events underscore the urgent need for climate adaptation and mitigation strategies.
Urgent Calls for Action
Japan and South Korea’s record-setting summers add to growing evidence of the global climate emergency. Policymakers in both countries face mounting pressure to accelerate carbon reduction commitments and strengthen resilience measures against extreme weather.
Additional resources on international climate action are available from the Intergovernmental Panel on Climate Change.
