Europe's Historic Spring Heat Dome

Beginning on May 24, a persistent high-pressure system described as a "heat dome" drew a mass of hot air from northern Africa across Western Europe, pushing temperatures a staggering 10 to 15°C above normal for the time of year . The result was a record-shattering heatwave that surpassed all-time marks for May and the entire meteorological spring in multiple nations.

A Timeline of Broken Records

• United Kingdom: On Monday, May 25, the temperature reached 34.8°C at London's Kew Gardens, a provisional new record. It was then beaten 24 hours later on Tuesday, May 26, soaring to 35.1°C (95.2°F) . This smashed the UK's previous May record of 32.8°C, which had stood for over a century, by a full 2°C .
• France: The country recorded its hottest May day ever, with a national average temperature of 24.4°C, breaking a record from 1944 . Temperatures locally soared to 37.8°C in the southwest, and for the first time since its creation in 2004, the national heat warning system was activated in May .
• Ireland and Portugal: Both nations also set new national May temperature records. Ireland recorded 28.8°C at two stations, while Portugal's central town of Mora hit a scorching 40.3°C, exceeding the previous 40°C record from 2001 .

The Early Heatwave's Deadly Toll

The extreme spring heat had immediate and fatal consequences, primarily from drowning as people sought relief in cold water. French authorities confirmed at least seven deaths directly or indirectly linked to the heat, including five drownings and two potentially heat-related fatalities at amateur sporting events . In the UK, a 13-year-old boy drowned in a reservoir in Halifax, northern England . Reports of other drownings were widespread, with the UK's Royal Life Saving Society issuing urgent water safety warnings after nine people died in open water during the hot spell .

The Looming Power of El Niño

The record May heat unfolded against a backdrop of rapidly changing conditions in the Pacific Ocean. Copernicus noted that sea surface temperatures remained at "exceptionally high levels" across a broad swath of the tropical Pacific . Climate models are in strong agreement that an El Niño event is imminent, with the International Research Institute for Climate and Society (IRI) assigning a 98% probability of its formation by the May-July 2026 period . The World Meteorological Organization (WMO) corroborated this, noting a "rapid warming trend" and a "nearly unanimous trajectory toward El Niño" .

Forecasts suggest the event could be severe. More than 50% of models in the C3S multi-system ensemble predict an amplitude exceeding 2.5°C in the Niño 3.4 index by early November 2026 . Such a strong El Niño would amplify global temperatures further and is expected to increase the risk of land and marine heatwaves, droughts, wildfires, and extreme rainfall events across the planet .

Global Disasters: Flooding in China and Turkey

While Western Europe baked, other regions were inundated by deadly floods, exemplifying the concurrent extremes of a warming world.

• China: In mid-May, the most powerful early-season storm in years unleashed torrential rain and flash floods across at least seven provinces in southern and central China. The death toll climbed to at least 22 people, with another 20 reported missing . Tens of thousands of residents were evacuated as the floods submerged towns, shut down schools and businesses, and disrupted major transport links .
• Turkey: In Hatay province, heavy overnight rains triggered severe flooding on May 21, causing road collapses and structural damage. At least two people were killed in the Antakya district when a hillside home collapsed onto a road .

A Clear Warning of a 'New Normal'

In response to the record-breaking spring heat, the EU's Copernicus monitor issued an explicit warning that these extremes represent a "new normal" . Carlo Buontempo, the director of C3S, and other scientists emphasized that climate change is making such intense and early heatwaves far more frequent and intense . The UN described the European heatwave as a "brutal reminder" of the reality of climate change, urging governments to accelerate both emissions cuts and adaptation to a world where historical records are regularly shattered .

The underlying driver, scientists reiterated, remains the continued combustion of fossil fuels. This relentless warming has made 2024 the planet's hottest year on record, 2025 the third-hottest, and is placing 2026 on track to be one of the warmest years ever recorded, with the added engine of a powerful El Niño set to intensify global temperatures in the months ahead .

Europe's Historic Spring Heat Dome

Beginning on May 24, a persistent high-pressure system described as a "heat dome" drew a mass of hot air from northern Africa across Western Europe, pushing temperatures a staggering 10 to 15°C above normal for the time of year . The result was a record-shattering heatwave that surpassed all-time marks for May and the entire meteorological spring in multiple nations.

A Timeline of Broken Records

• United Kingdom: On Monday, May 25, the temperature reached 34.8°C at London's Kew Gardens, a provisional new record. It was then beaten 24 hours later on Tuesday, May 26, soaring to 35.1°C (95.2°F) . This smashed the UK's previous May record of 32.8°C, which had stood for over a century, by a full 2°C .
• France: The country recorded its hottest May day ever, with a national average temperature of 24.4°C, breaking a record from 1944 . Temperatures locally soared to 37.8°C in the southwest, and for the first time since its creation in 2004, the national heat warning system was activated in May .
• Ireland and Portugal: Both nations also set new national May temperature records. Ireland recorded 28.8°C at two stations, while Portugal's central town of Mora hit a scorching 40.3°C, exceeding the previous 40°C record from 2001 .

The Early Heatwave's Deadly Toll

The extreme spring heat had immediate and fatal consequences, primarily from drowning as people sought relief in cold water. French authorities confirmed at least seven deaths directly or indirectly linked to the heat, including five drownings and two potentially heat-related fatalities at amateur sporting events . In the UK, a 13-year-old boy drowned in a reservoir in Halifax, northern England . Reports of other drownings were widespread, with the UK's Royal Life Saving Society issuing urgent water safety warnings after nine people died in open water during the hot spell .

The Looming Power of El Niño

The record May heat unfolded against a backdrop of rapidly changing conditions in the Pacific Ocean. Copernicus noted that sea surface temperatures remained at "exceptionally high levels" across a broad swath of the tropical Pacific . Climate models are in strong agreement that an El Niño event is imminent, with the International Research Institute for Climate and Society (IRI) assigning a 98% probability of its formation by the May-July 2026 period . The World Meteorological Organization (WMO) corroborated this, noting a "rapid warming trend" and a "nearly unanimous trajectory toward El Niño" .

Forecasts suggest the event could be severe. More than 50% of models in the C3S multi-system ensemble predict an amplitude exceeding 2.5°C in the Niño 3.4 index by early November 2026 . Such a strong El Niño would amplify global temperatures further and is expected to increase the risk of land and marine heatwaves, droughts, wildfires, and extreme rainfall events across the planet .

Global Disasters: Flooding in China and Turkey

While Western Europe baked, other regions were inundated by deadly floods, exemplifying the concurrent extremes of a warming world.

• China: In mid-May, the most powerful early-season storm in years unleashed torrential rain and flash floods across at least seven provinces in southern and central China. The death toll climbed to at least 22 people, with another 20 reported missing . Tens of thousands of residents were evacuated as the floods submerged towns, shut down schools and businesses, and disrupted major transport links .
• Turkey: In Hatay province, heavy overnight rains triggered severe flooding on May 21, causing road collapses and structural damage. At least two people were killed in the Antakya district when a hillside home collapsed onto a road .

A Clear Warning of a 'New Normal'

In response to the record-breaking spring heat, the EU's Copernicus monitor issued an explicit warning that these extremes represent a "new normal" . Carlo Buontempo, the director of C3S, and other scientists emphasized that climate change is making such intense and early heatwaves far more frequent and intense . The UN described the European heatwave as a "brutal reminder" of the reality of climate change, urging governments to accelerate both emissions cuts and adaptation to a world where historical records are regularly shattered .

The underlying driver, scientists reiterated, remains the continued combustion of fossil fuels. This relentless warming has made 2024 the planet's hottest year on record, 2025 the third-hottest, and is placing 2026 on track to be one of the warmest years ever recorded, with the added engine of a powerful El Niño set to intensify global temperatures in the months ahead .