The European Union’s official climate monitoring body confirmed Thursday that 2025 has brought Western Europe its hottest June ever recorded, capping off a month of unprecedented extreme heat that has underscored the accelerating impacts of human-caused climate change across the continent. The announcement comes as a second intense heatwave already bears down on Europe this summer, following the June record-breaking event and an unseasonably early spring heatwave that struck in May.
Data from the EU’s Copernicus Climate Change Service shows the average June temperature across Western Europe hit 20.74°C this year – more than 3°C higher than the 1991-2020 baseline average for the month. The figure shatters the previous regional June record set just two years prior in 2025. For the globe as a whole and Europe as an entire continent, this June ranked as the second hottest ever recorded, Copernicus confirmed, as decades of greenhouse gas emissions continue to drive global average temperatures steadily upward.
Global average June temperatures this year hit 1.39°C above the pre-industrial baseline (1850-1900), the service reported. The world’s oceans also logged their warmest June on record, compounded by a developing El Niño weather pattern in the tropical Pacific that forecasters project will strengthen in the coming months.
The record-breaking June heat was driven by a stubborn “heat dome” – a persistent high-pressure system that traps hot air like a lid over a boiling pot – that settled over much of Western Europe, pushing multiple countries to break both monthly and all-time high temperature records. An analysis by Agence France-Presse found that more than 410 million Europeans – over two-thirds of the region’s population – faced temperatures above 35°C between June 15 and 30. Thousands of heat-related deaths were recorded across the continent, concentrated primarily in France, Spain and Belgium, with high humidity amplifying the danger by preventing cooling overnight.
“It was extremely humid, which then meant people didn’t get relief at night. So we had a number of tropical nights in a row,” explained Samantha Burgess, strategic climate lead at the European Centre for Medium-Range Weather Forecasts (ECMWF), which manages the Copernicus program. Warm ocean waters along Europe’s Mediterranean and Atlantic coasts compounded the issue, eliminating cooling sea breezes that typically bring overnight relief. The Mediterranean also saw a record-breaking marine heatwave that put coastal and marine ecosystems at severe risk.
Dry conditions from the heat also exacerbated drought risks in Eastern Europe and amplified wildfire activity across the Iberian Peninsula and Southern France, Copernicus noted.
Climate scientists from World Weather Attribution, an international research network, previously classified the June 2025 heatwave as the most severe ever recorded in Europe based on three-day peak average temperature forecasts across the affected region. The group concluded the event would have been virtually impossible to occur without the influence of human-caused climate change; a similar heat event in June 2003 would have been roughly 2°C cooler, they found.
Burgess warned that heat extremes will only become more common, intense and widespread as global temperatures continue to rise. “We will see more heatwaves in a warmer world. They will be more intense and they will last longer, and they will impact more geographical areas,” she told AFP. She added that climate change is no longer a distant future threat, but a disruptive force already reshaping daily life: “We’re at a transition point where climate change is shifting from being an abstract statistical future problem that you read about in reports, to a concrete present and disruptive feature of daily life.”
Europe, which is already the fastest-warming continent on Earth, faces unique challenges as it adapts to this new climate reality, Burgess noted. Many of the region’s most iconic historic buildings were constructed centuries ago for a cooler climate that no longer exists, requiring urgent updates to built infrastructure to protect residents from extreme heat. To slow the progression of worsening heat extremes, Burgess emphasized that the world must reach net-zero greenhouse gas emissions from fossil fuel combustion as quickly as possible. “Heatwaves will only get worse the more (emissions from) fossil fuel we pump into the atmosphere,” she said.