The summer of 2025 has rewritten climate history as the United Kingdom, Japan, and South Korea endured their hottest summers since records began. Weather agencies in all three countries confirmed the unprecedented temperature spikes, highlighting the escalating impacts of human-driven climate change.
Record Temperatures Across Three Nations
The UK’s provisional mean temperature between June and August stood at 16.1°C, which is 1.51°C above the long-term average. This surpassed the record set in 2018 and marked the hottest summer since records began in 1884. Four heatwaves, below-average rainfall, and extended sunshine added to the pressure, following the country’s warmest spring in over a century.
Japan reported an even sharper increase. The average summer temperature rose 2.36°C above the standard value, making it the hottest summer since records began in 1898. It was the third consecutive year of record-breaking summer heat. From May to late August, more than 84,000 people were hospitalized nationwide due to heat-related illnesses.
In South Korea, the average summer temperature was 25.7°C, the highest since record-keeping began in 1973. This figure surpassed last year’s record of 25.6°C, reflecting a consistent rise in heat extremes.
Struggles in Daily Life
The UK, known for its damp and mild climate, struggled with heat preparedness. Many homes are designed to retain heat, not release it, and air conditioners are rare in residences and public spaces. London’s underground transport system, heavily used by commuters, became particularly challenging during heatwaves.
Japan also faced lifestyle adjustments. Many residents avoided outdoor activities, with younger generations noting how summers have shifted from playtime outdoors to spending more time inside. Experts warned that climate change is also disrupting natural cycles, such as cherry tree blossoms, which either bloom earlier or incompletely due to milder winters. Even Mount Fuji’s iconic snow cap appeared later than usual last year, signaling further ecological change.
South Korea’s challenges went beyond the heat. A prolonged drought in the coastal city of Gangneung forced authorities to declare a state of national disaster. Water levels in the Obong reservoir dropped below 15 percent, leading to strict water rationing, including shutting off most household meters.
Climate Experts Raise Alarm
Meteorological experts linked the extreme summer heat to the weakening of Arctic cold air, a consequence of global warming. Scientists warned that as this trend continues, similar extreme weather patterns are likely to repeat in the coming years.
The Met Office projected that summers as hot or hotter than 2025 are now 70 times more likely than they would be in a natural climate without human-induced greenhouse gas emissions. This alarming increase underscores the accelerating impact of climate change.
A Global Climate Emergency
These record-breaking summers in the UK, Japan, and South Korea are not isolated events. Globally, heatwaves are intensifying due to climate change, with Europe experiencing the fastest warming per decade since 1990, followed closely by Asia.
The United Nations recently warned that rising temperatures are not only damaging ecosystems but also harming human health and productivity. According to their findings, productivity falls by two to three percent for every degree above 20°C, especially affecting outdoor workers.
The summer of 2025 has become a turning point in climate records, exposing vulnerabilities in infrastructure, healthcare, and ecosystems. The experiences of the UK, Japan, and South Korea serve as urgent reminders that climate adaptation and mitigation must accelerate. Without decisive global action, extreme summers will only become more common, with devastating consequences for people and the planet.
