Extreme heat and flash floods: Scientists warn of hazardous summer weather in Europe

Europe could be in for a summer of extreme heat and flash floods, climate scientists have warned, after parts of the continent were rocked by soaring temperatures and severe storms.

While the UK experienced a wet and mild June, much of the rest of Europe has been hit by extreme weather, including heatwaves and flooding.

Flights heading to Palma Airport, on the popular tourist island of Mallorca, had to be rerouted last week following heavy rainfall that caused flooding on the Balearic Islands and parts of mainland Spain.

It came one week after flooding resulted in mass cancellations across Germany’s railway system.

Water from the swollen Danube River flows on the town hall square on June 5, 2024 in Passau, Germany. (Photo by Lukas Barth/Getty)

Meanwhile, schools and popular tourist sites were closed across Greece last week as the country experienced a heatwave that saw temperatures reach as high as 43C. The heatwave has been linked to a number of tourist deaths, including British broadcaster Dr Michael Mosley.

The scenes have left climate scientists worried that Europe could be in for another summer of extreme weather, following the record-breaking heatwave of 2023.

Another summer of extreme heat

Last year was the hottest on record, bringing extreme heat, wildfires and flooding to large parts of Europe throughout the summer.

Scientists attributed the alarming temperatures to climate change, combined with the impact of an El Niño weather event.

Every two to seven years, climate patterns in the eastern Pacific Ocean switch between El Niño and La Niña phases. The former leads to unusually warm surface waters, while the latter leads to unusually cold water. There is typically a neutral period in between.

Dr Neven Fučkar, a climate scientist based at the University of Oxford, told i the Pacific is now entering a neutral phase, but it is not yet clear how quickly the La Niña phase will develop.

While Dr Fučkar said he “hopes” Europe will not break as many heat records as last year, he said public authorities should be “cautious” and “expect the same amount of extreme heat as last summer”, noting that temperatures above 40C have already been seen in Greece.

A man cools down with water from a fountain as a heatwave hits Athens, Greece, on 13 June (Photo: Reuters/Stelios Misinas)

The entrance of a closed primary school in Thessaloniki on 12 June 2024. Schools will remain closed, public servants will work from home, and deliveries will not be made amid a mini-lockdown due to this summer’s first major heatwave, which has also put authorities on standby for the power supply. (Photo by Sakis Mitrolidis/AFP)

A major heatwave is also expected across parts of Europe this week, with temperatures in the mid-30s forecast across central Europe, the Balkans and Eastern Europe.

Dr Chloe Brimicombe, a climate scientist based at the University of Graz in Austria, said she thinks Europe “will see something similar [to last year] because this has been the play by play year-on-year. We’ve had 12 months of above average temperatures now”.

While the impact of El Niño may be lessening, scientists warn the impact of global warming is only increasing over time.

Dr Liz Bentley, chief executive at the Royal Meteorological Society, said the current heatwave in Greece will be “impacted significantly [by] climate change”.

An analysis published this week by the non-profit Climate Central found the recent heatwave in south east Europe was made five times more likely as a result of climate change.

Supercell storms and flooding

Alongside the extreme heat, scientists are worried that Europe is likely to experience more flash flooding this summer, similar to that seen in Spain and Germany in recent weeks.

Dr Bentley said the recent flooding was the result of an “extreme contrast in temperature” between the south east and north west of Europe in recent weeks.

While parts of southern Europe have experienced heatwaves, cold air from the Arctic has resulted in below average temperatures in the UK and other parts of northern Europe.

When this occurs, large tornado-like storm clouds, known as “supercells” can form, resulting in extreme rainfall, strong winds and hail.

Dr Bentley said these supercells are more commonly witnessed in the US, but said Europe currently has the “ingredients” to produce these, as was seen in parts of Spain last week.

Floodwater flows beneath a building after heavy rain quickly raised the water levels in Murcia, Spain on 12 June 2024 (Photo: @AndreiitaaMc/Reuters)

Thunderstorms are expected in Germany and parts of France this week.

Dr Brimicombe said she was worried that Europe could be more susceptible to flash flooding this summer due to the particularly wet spring experienced across much of the continent.

“The soil is already containing a lot of water and that means that it can’t contain that much more. We have heatwaves and then in a lot of cases we have thunderstorms. So that is also a concern,” she said.

Preparing for extreme weather

Dr Fučkar said it was important that local authorities across Europe develop action plans for extreme weather this summer.

He said Britons travelling to other parts of Europe this summer should “check the weather forecast every morning and adjust their plans accordingly”.

He also stressed that it was important people were careful while remaining in the UK, noting the record-breaking temperatures experienced in recent summers.

Dr Ilan Kelman, a climate scientist at University College London, also issued a warning to those who find themselves in extreme heat this summer.

“Number one: watch the forecast. Number two: where there is going to be heat be careful, particularly during the worst part of the day, between noon and 3pm. Stay cool, stay hydrated and ensure that if you are particularly susceptible to heat, you’re even more cautious, so children and retired people.”