Europe swelters under 'historic and unprecedented' May heatwave, shattering records from London to Paris

A ferocious and historically early heatwave has seized control of Western Europe, shattering long-standing temperature records and forcing authorities across multiple nations to implement emergency measures. The extreme weather, driven by a 'heat dome' trapping hot air from North Africa, has pushed the mercury to levels typically unseen even at the peak of summer.

Record temperatures across the continent

On Monday, the United Kingdom recorded its hottest May day ever, with the temperature reaching 34.8°C at Kew Gardens in London, smashing the previous record of 32.8°C set in 1922 and matched in 1944. The Met Office confirmed that Tuesday was expected to be even hotter, with a new record of 35°C registered in the capital. Ireland also set a new May record, with 28.8°C recorded in Killarney and Clonmel. In France, Météo-France reported that over 350 monthly heat records were broken or equalled on Monday alone, with temperatures ranging from 33 to 36°C across the country.

We are running out of superlatives to describe it. It is exceptional, unprecedented, historic. First by its precocity, but also its intensity and duration.

The 'heat dome' phenomenon

The scorching temperatures are the result of a 'heat dome', a zone of high pressure that has settled over Western Europe, compressing and trapping a mass of hot air originating from North Africa. This meteorological blockage has caused temperatures to skyrocket since the Pentecost weekend. Forecasters warn that the heat will persist, with a general drop in temperatures not expected until Sunday, potentially accompanied by thunderstorms.

On Thursday, we will see a slight shift of the very high heat towards the South and East. We could very locally have 38°C, even 39°C in certain regions, notably in Languedoc, which would be totally unprecedented.

Cascading disruptions and safety measures

The extreme heat has triggered a cascade of disruptions. In the Netherlands, the army temporarily suspended all military activities involving firearms and explosives in the Gelderland region after the wildfire risk was raised to level 2. In the UK, South Western Rail cancelled several trains on lines between London and the South West due to the heat and initiated network-wide inspections. A vegetation fire broke out on Arthur's Seat in Edinburgh as temperatures climbed to 25°C.

In Germany, authorities in Jülich, North Rhine-Westphalia, issued a water shortage warning, urging residents to use drinking water 'very sparingly' and to avoid watering lawns or filling pools. In Italy, the Lazio region, which includes Rome, approved rules limiting prolonged outdoor work in sectors like agriculture, construction, and logistics between 12:30 and 16:00, effective from 25 May to 15 September.

France on high alert

France has been particularly hard hit. Météo-France placed 13 departments in the west of the country on orange heatwave alert (the second-highest level) for Wednesday, with a yellow alert extending to 29 departments. The heat has already had fatal consequences, with seven deaths attributed to the high temperatures, including one person who died during a 10 km race in Paris and ten others who were hospitalised in critical condition after a race in Maisons-Alfort. Spectators at the Roland-Garros tennis tournament in Paris also endured difficult conditions with temperatures exceeding 33°C.

We are observing more and more records being broken, and more and more often. It is a good indicator of climate change at work.

A climate change warning

Climatologists have been unequivocal in linking the event to human-caused climate change. Météo-France climatologist Matthieu Sorel stated that while the episode is not surprising given decades of scientific warnings, it remains shocking. He noted that such temperatures, currently exceptional, are set to become a regular occurrence by the middle of the century and almost constant by its end. The scientific consensus holds that climate change is making extreme weather events like heatwaves, droughts, and floods more intense.

A continent on edge

From the 'tropical' nights in Brittany, where temperatures stayed above 20°C, to the parched parks of London, the heatwave is a stark reminder of Europe's vulnerability. As the continent, which is warming faster than the global average, braces for the heat to intensify towards the weekend, the immediate focus remains on protecting public health and preventing wildfires.