Europe Heatwave Virtually Impossible Without Climate Change

A record-shattering heatwave that has gripped Europe in June 2026 would have been virtually impossible without human-caused climate change, according to a new analysis by World Weather Attribution (WWA). The study, released June 26, finds that daytime temperatures during the heatwave are about 3.5°C hotter than a similar event in 1976, and that such extreme heat is now at least ten times more likely than during the deadly 2003 European heatwave.

What the Attribution Study Found

Scientists from the international research network WWA, including experts from the Royal Netherlands Meteorological Institute (KNMI), used weather observations and climate models to compare today's heatwave with a hypothetical version in a world without global warming. Their conclusion is stark: the June 2026 heatwave—the most severe ever recorded over the region studied—was made significantly more intense and far more likely by the buildup of greenhouse gases from burning fossil fuels.

"This heatwave is unmistakably caused by climate change," said KNMI researcher Sjoukje Philip, who contributed to the report. "We see that the same weather patterns that would have produced moderate heat fifty years ago now produce dangerously extreme temperatures."

The analysis found that a similar heatwave in 1976 would have been about 3.5°C cooler during the day and 2.4°C cooler at night. Compared to the 2003 heatwave—the first major event of the millennium—daytime temperatures are now about 2°C hotter, and nighttime temperatures are 1.3°C warmer. The link between climate change and extreme weather is becoming increasingly clear with each passing season.

Record-Breaking Temperatures Across Europe

The heatwave, driven by a Saharan heat dome, pushed temperatures 5–12°C above seasonal averages across France, Germany, Italy, Spain, the United Kingdom, and the Netherlands. France recorded its hottest day ever at 44.3°C in Pissos on June 24. The UK experienced its highest June temperature on record, while the Netherlands issued its first-ever code red warning for extreme heat, covering eight provinces.

"The fact that we are seeing code red for heat—something never done before—shows how exceptional this event is," said a KNMI spokesperson. The Dutch weather service warned that even healthy individuals face risks of dehydration, overheating, and heatstroke.

Nighttime Heat: A Growing Health Threat

One of the most concerning findings is the surge in nighttime temperatures. The WWA study found that dangerously warm nights are now about 100 times more likely than during the 2003 heatwave. "If you can't cool down at night, the effects of heat become progressively worse," Philip explained. "The body doesn't get a chance to recover."

The wet-bulb globe temperature (WBGT)—a measure combining heat and humidity that reflects how conditions feel to the human body—reached record levels in nearly 45% of 854 European cities analyzed. In the Netherlands, 90% of cities recorded their highest-ever wet-bulb temperatures during this period, signaling extreme heat stress. This is closely tied to the growing risks of urban heat islands in densely populated areas.

Fatalities and Societal Disruption

The human toll is mounting. At least 290 deaths have been attributed to the heatwaves across Europe, including 212 in Spain, 58 in France, and 20 in the UK. France reported 40 drowning deaths as people sought relief in rivers and lakes. Hospitals have seen a sharp rise in heat-related admissions, and power outages have affected thousands of households as air conditioning use strains the grid.

School closures, rail speed restrictions, and water shortages have become widespread. In Spain, temperatures exceeded 40°C in multiple cities, while Portugal's Mora station hit 40.3°C in late May. The economic impact is estimated in the billions of euros, with agriculture, tourism, and energy sectors all affected.

"Heatwaves kill more Europeans than all other natural hazards combined," the WWA report notes. Over 60,000 people died during the summer 2022 heatwaves alone. The urgent need for heat adaptation strategies has never been more apparent.

El Niño Not a Factor

The researchers also investigated whether the El Niño climate pattern contributed to the heatwave. Their conclusion: El Niño played no role. "The extreme heat is entirely driven by human-caused climate change," said Friederike Otto, a leading climate scientist at Imperial College London and co-founder of WWA. "The weather patterns themselves are not unusual—it's the temperature baseline that has shifted."

Europe Warming Faster Than Global Average

Europe is the world's fastest-warming continent, heating at roughly twice the global average since the 1980s. The WWA analysis shows that the hottest daytime temperatures in Western Europe are warming at about three times the global average rate. This is partly because land warms faster than ocean, and because summer winds increasingly bring hot air from North Africa.

"The difference with 2003 is remarkable," Philip said. "Most people remember that heatwave. You can see within a single human lifetime what climate change has done."

FAQ: Europe Heatwave and Climate Change

What is the World Weather Attribution study?

WWA is an international scientific collaboration that rapidly analyzes extreme weather events to determine how much climate change influenced their intensity and likelihood. Their June 2026 study focused on the European heatwave.

How much more likely is this heatwave due to climate change?

The study found the heatwave is at least 10 times more likely than in 2003, and nighttime heat is about 100 times more likely. Compared to 1976, such an event would have been virtually impossible without global warming.

What is wet-bulb globe temperature and why does it matter?

WBGT measures heat stress on the human body by combining temperature, humidity, wind speed, and solar radiation. High WBGT values indicate dangerous conditions that can lead to heat stroke or death, especially for vulnerable populations.

Did El Niño cause the 2026 heatwave?

No. The WWA analysis found that El Niño played no role in the current heatwave. The extreme temperatures are attributed entirely to human-caused climate change.

What can be done to prevent future heatwaves?

Scientists emphasize the urgent need to phase out fossil fuels, reduce greenhouse gas emissions, and adapt infrastructure—including urban green spaces, cooling centers, and heat-health warning systems—to cope with rising temperatures.

Sources

World Weather Attribution, Heatwave analysis page; KNMI; NOS; New York Times; US News & World Report; Wikipedia: 2026 European heatwaves.