Widespread Heat Across Western Europe
Currently, much of western Europe is experiencing intense heat, with few areas escaping the high temperatures.
In the UK, temperatures exceeded 35C on Tuesday, surpassing the previous May record by over 2C. The Met Office notes that such heat would be extraordinary even during mid-summer, let alone in spring.
"Absolutely astonishing," says Friederike Otto, professor of climate science at Imperial College London.
"Mind-bogglingly crazy," adds Peter Thorne, director of the Icarus Climate Research Centre at Maynooth University in Ireland.
France is also enduring an unprecedented early-season heatwave, with its weather service, Météo-France, reporting hundreds of broken heat records nationwide.
Meanwhile, Ireland’s May temperature record was exceeded by more than 1C, and countries including Germany, Italy, Spain, and Switzerland have all experienced unusually warm spring conditions.
Causes of the Heatwave
The immediate cause of this heatwave is a "heat dome," a phenomenon where a high-pressure system becomes stationary over Europe, trapping warm air beneath it.
Scientists widely agree that human-induced climate change, primarily from burning coal, oil, and gas, has intensified this heat.
Over the past 30 years, Europe’s temperature has risen by 0.56C per decade, more than twice the global average, according to the Copernicus climate service. Although this increase may seem modest, it represents a significant climatic shift that amplifies the severity of heat extremes.
"When we have a heatwave it's happening more severely, because it's on top of a warming climate," Richard Betts, head of climate impacts research at the Met Office and professor at the University of Exeter, told .
"I've been a climate scientist for 33 years and we're seeing exactly the kinds of things that we were warning back then... [although] these records are perhaps more extreme and coming sooner than we had expected," he added.
The heatwave is not confined to Europe; for example, temperatures in Delhi, India, have reached 45C.
Records Not Just Broken but Smashed
In a stable climate, temperature records should become less frequent over time as more data accumulates. Statistically, new records are more likely after fewer years of measurement than after many decades.
"If someone beats a world record in high jump, you would expect them to beat it by one centimetre and not suddenly by 20, 30 centimetres and the same holds for the weather," said Erich Fischer, professor at the Institute for Atmospheric and Climate Science at ETH Zurich in Switzerland.
"If the record is broken after 100 or 150 years of measurements, you would have probably expected it to be broken by a tenth of a degree and not suddenly by two degrees or three degrees," he added.
However, when a rare weather event like this week’s heat dome occurs in a warming climate, the margin by which records are broken can be substantial.
"We're going through a period of very rapid warming, particularly western Europe… so if the same weather events we had in, say, the 1970s [happened again], it will not only be slightly warmer, but it will simply smash the record," said Prof Fischer.
This week’s European heatwave is not an isolated incident even in 2026. In March, approximately 30% of active US weather stations set new temperature records for that time of year, according to Berkeley Earth, an independent US climate research group.
The margin of records across the western US was "utterly absurd," said Robert Rohde, Berkeley Earth's chief scientist.
A Sign of Things to Come
These record-breaking heatwaves are occurring in a world that is on average 1.4C warmer than the late 19th century due to human activities such as fossil fuel combustion.
Projections indicate that global warming could approach 3C by the end of the century based on current government climate policies worldwide.
This increase will inevitably lead to further temperature records, posing significant challenges for countries like the UK and Switzerland, which are not designed to handle extreme heat.
Recent events demonstrate that this challenge is no longer limited to summer months.
"The climate we are living in today is simply not the one we grew up with, and our buildings and infrastructure are woefully unprepared for what's next," warned Prof Otto.
Until 1990, the UK's highest temperature record across all months was 36.7C, set in 1911. Since then, it has been broken multiple times, most recently reaching 40.3C in July 2022.
Prof Betts cautioned that with ongoing climate change, even higher temperatures are a serious possibility.
"Until we reduce global carbon emissions to net zero, we'll continue to heat the planet and temperature records will continue to be broken," he said.
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