The European climate agency Copernicus concludes that last summer was the hottest Western European summer on record. The average temperature was 21.7 degrees, 2.5 degrees warmer than the 1991-2020 summer average, according to the latest Copernicus Climate Change Service (C3S) European Summer Review 2026, published on 2 October.

Copernicus highlights the far-reaching consequences of these climate extremes for “water resources, energy systems, transport, ecosystems, and human health.” The report combines data on temperature, heat stress, rainfall, soil moisture, river flow, sea temperatures, and wildfires. 

Seasonal records

Seasonal summer average temperatures were much warmer than average over 41% of European land, mainly in western and central Europe, and reached record highs over 22% of the land area. Seasonal records were set across virtually all of England, Wales and Belgium, as well as large parts of France, Spain, Italy, Switzerland and Austria.

Record-hot summers were reported across large parts of Europe, including Belgium, the Netherlands, France, the UK, Spain, and Austria.

Copernicus registered a record 41 days of ‘strong heat stress’ and a record 13 days of ‘very strong heat stress’. Apparently, every Western European summer since 2015 has been warmer than the 1991-2020 average.

High seawater temperatures

Moreover, the heat persisted for an exceptionally long time and spread over a wide area. It was also warm elsewhere in Europe: the entire continent experienced its third-warmest summer on record. 

As always with climate-change-driven warming, seawater absorbed much of the impact. The North Sea reached its highest-ever temperature in August.

Warming seawater is rapidly disrupting underwater life. In the long run, this warming could also amplify the effects of climate change: warmer seawater can absorb less greenhouse gas from the atmosphere.

Extreme low river water levels

In addition to being warm, it was also dry: the latest figures show that Copernicus has recorded the lowest water levels in European rivers since measurements began in 1992.

Large stretches of the Rhine, Danube, Seine, Loire, Rhône and Vistula reached exceptionally low seasonal flows, turning climate into a mobility and economic story: inland shipping, industrial supply chains, hydropower, cooling water and agriculture were all affected. 

Likelihood of records increases

However, this does not mean that Western Europe will now set a new summer-temperature record every single year. Weather variability remains large. The weather still determines where an individual year lands; greenhouse warming progressively raises the platform underneath it.

Still, the likelihood of records nevertheless increases because Europe is warming substantially faster than the planet overall. Copernicus currently estimates that, over roughly the past 30 years, global warming will be about +0.27°C per decade, and European warming about +0.56°C per decade, although atmospheric circulation, aerosols, snow cover, ocean behavior, and future emissions all matter.

Unprecedented rate of global warming

The Earth has actually been this hot before. Go back tens of millions of years and the planet experienced climates considerably warmer than ours. Even during the previous interglacial about 125,000 years ago, global multi-century temperatures were likely somewhere around or somewhat above modern levels. The only problem is, we don’t have data for it. “Warmest summer on record” means within the modern observational period. 

What makes today’s situation unusual isn’t simply the absolute temperature; it’s primarily the speed, geographical scale, and cause of the warming.

The IPCC concludes that the rate of global warming during the past roughly 50 years is unprecedented in at least 2,000 years. The planet warmed about 5°C between the last ice age and today’s interglacial, but that transition occurred over thousands of years rather than a century or two.

Previous warm periods were driven by factors such as Earth’s orbital changes, solar effects, volcanism, and continental configuration, whereas modern warming has a very different fingerprint.

The IPCC assesses that human influence is unequivocally responsible for the dominant part of the recent warming and that human-induced climate change is the principal driver behind the observed increase in heat extremes.