UK heatwaves will become more deadly due to climate change, experts warn, as temperatures set to hit 34C

Extreme weather increasingly likely during British summers – and Friday could be hottest June day on record

A man checks his phone as he walks through the heat in St James’s Park, London (Getty Images)

The weather is warm and sunny and summer has arrived in the UK. But even as people dust down their deckchairs and crack out the suncream, the Met Office has issued heat alerts, with the soaring temperatures leaving the country on the cusp of a dangerous heatwave.

Forecasters have warned that Friday could be a contender for the hottest June day on record, with highs in parts of the south east approaching 34C (93F).

“Reaching 34C during June is a rare, but not unprecedented event in the historical climate records for the UK. But if it should happen this week it would be notable that it would have occurred on three days during the last six Junes,” said Dr Mark McCarthy, head of the Met Office’s National Climate Information Centre.

He warned that the climate crisis “has increased the average temperature of UK summers, and it is also increasing the likelihood of experiencing more extreme temperatures during hot spells and heatwaves”.

The unusally warm weather has led some experts to warn of the “serious” health implications the sweltering heat can bring.

Dr Vikki Thompson, climate scientist at the University of Bristol Cabot Institute for the Environment, said: “Heatwaves are one of the most deadly natural hazards; in the UK 3,000 deaths were linked to heatwaves in 2021.

“The health issues related to heat include direct effects, such as heatstroke and cardiovascular failure, and indirect effects including poorer mental health and an increase in accidents such as car crashes and drownings.”

Scientists have called for a “consolidated effort to reduce net emissions”, to avoid worsening the extreme-heat events.

Dr Edward Gryspeerdt, a research associate at Imperial College London’s Grantham Institute, told The Independent: “Climate change has increased the average temperature of UK summers, and it is also increasing the likelihood of experiencing more extreme temperatures during hot spells and heatwaves.”

But he warned against linking all heatwave incidents to the climate crisis without looking at broader patterns in the temperature records.

He said: “Heatwaves occur as part of natural climate and weather variation. As the weather in the UK is very variable and heatwaves are relatively rare, it can be difficult to link any one particular event to climate change.

“However, we know that heatwaves become hotter and much more likely as the world warms. Global land temperatures have increased by over 1C since the industrial revolution – a heatwave like the one in 2018 is now more than 30 times more likely than it would have been naturally.”

Dr Gryspeerdt’s colleague at the Grantham Institute, research associate Dr Mariam Zachariah, told The Independent that the increasing numbers of heatwaves have grave global consequences, but could also help people grapple with the magnitude of the climate crisis.

She said: “Heatwaves have direct implications for both health and food security, and therefore can help the public understand the impact of climate change.

“While timely advice and warning can help people stay safe and lessen health-related impacts, the adverse effect of high temperature on agriculture will be felt much later, as food scarcity or higher prices.

“In addition to these direct effects, heatwaves can also trigger other hazards such as flash floods due to accelerated glacial melt, as happened in Pakistan during the widespread and persistent heatwave in South Asia earlier this year.”

In the UK, she said, the average duration of warm spells has more than doubled in the last two decades.

This has seen an increase in both the hottest and lowest temperatures by 0.8C and 1.7C, respectively.

“Heatwaves are much less common in the UK when compared with the tropical countries, but in keeping with these observed trends in temperatures in the UK we can expect heatwaves to become longer, hotter and approaching deadly levels under unmitigated climate change.”

Additional reporting by PA