A woman holds an umbrella to shield from the summer heat in Japan (AFP)

Both Japan and South Korea experienced record-breaking temperatures during the summer of 2025, amid increasing severe heatwaves worldwide caused by climate change leading to more extreme and volatile weather conditions.

The Japan Meteorological Agency stated that the average temperature in Japan from June to August was 2.36°C above the normal average, making this summer “the hottest ever recorded since data collection began in 1898.”

The agency added that this marks “the third consecutive year of record summer temperatures” in Japan.

In South Korea, the Korea Meteorological Administration announced the average temperature during the same period reached 25.7°C, “the highest since data collection began in 1973.” The previous highest temperature for this period was 25.6°C last summer.

The severe heatwave in Japan led to 84,521 hospital admissions nationwide from May 1 to August 24, according to the Fire and Disaster Management Agency. This figure represents a slight increase compared to 83,414 admissions during the same period in 2024.

In Tokyo, 80-year-old runner Masao Nakano expressed nostalgia for the old days when he could simply “go outside, sprinkle water on the street, and breathe fresh air,” explaining that he managed to get through this hot summer by exercising in an air-conditioned gym and training for a marathon.

Due to rising temperatures, cherry trees, a charming sight in the archipelago, now bloom earlier in spring and their branches fail to flower properly because autumn and winter are no longer cold enough to stimulate blooming.

Meanwhile, Mount Fuji’s famous snowy cap appeared only in early November last year, whereas it usually appears in early October. Climate warming is one factor explaining the slow snow accumulation.

Conversely, South Korea faces a prolonged drought affecting the coastal city of Gangneung in the northwest. A national disaster was declared in this city of 200,000 residents after weeks without rain, and authorities imposed strict water use restrictions.

Scientists indicate that heatwaves have become more intense and frequent worldwide due to human-induced climate change. However, the rate of temperature increase varies globally. According to data from the US National Oceanic and Atmospheric Administration, Europe is the continent experiencing the fastest warming rate from decade to decade since 1990, followed by Asia.