High temperature records were smashed all across the UK last year during a searing summer heatwave.
Thermometers rose over 40C for the first time, reaching a baking 40.3C in England, 37.1C in Wales and even Scotland sweltered in 35.1C.
Now scientists are predicting super-hot days are likely to be hotter still, thanks to the impacts of climate change, with England, Wales and northern France predicted to feel the biggest effects.
Although climate predictions accurately forecast the increase in warming for average days, academics say the rise in temperature on the hottest days has been underestimated.
The indication comes as the Met Office warns this year is set to be another scorcher in the UK, after 2022 scooped the title as the hottest yet.
New analysis from the University of Oxford shows the hottest days in north-west Europe are heating up at double the rate of average summer temperatures, with the difference in trends most pronounced for England, Wales and northern France.
According to lead researcher Dr Matthew Patterson, from the university’s Department of Physics, the results suggest extreme heat events such as last summer’s record-breaking hot spell are likely to become more commonplace as global warming continues.
“These findings underline the fact that the UK and neighbouring countries are already experiencing the effects of climate change, and that last year’s heatwave was not a fluke,” Dr Patterson said.
He warned steps must be taken to safeguard people and prepare for regular searing heat, adding: “Policy-makers urgently need to adapt their infrastructure and health systems to cope with the impacts of higher temperatures.”
The Oxford team arrived at the conclusion after studying temperature records dating back to 1960. Although the top temperature varied between years, the overall pattern showed the hottest days for north-west Europe had warmed at double the rate of average summer days.
For England and Wales, temperatures on the average summer day rose by 0.26C every decade, whilst the hottest day increased by around 0.58C over the same period. However, this faster warming of the hottest days was not as marked elsewhere in the northern hemisphere.
The team is not yet sure what is behind the greater rise in north-west Europe, but it is thought it could be a knock-on effect from blistering heat further south.
Data shows the hottest days of 2022 were driven by a plume of hot air carried north from Spain and the Sahara desert. Extreme heat can be dangerous, particularly for very young children and old people and those with existing health conditions. It can also cause significant problems for transport, energy and agriculture.
Both the UK and Scottish governments have come under fire from advisers over insufficient action to combat climate change. Dr Patterson stressed the need for further research and preparations for future warming.
“Understanding the warming rate of the hottest days will be important if we are to improve climate model simulation of extreme events and make accurate predictions about the future intensity of such events,” he said. “If our models underestimate the rise in extreme temperatures over the coming decades, we will underestimate the impacts this will have.”
The study is published in the journal Geographical Research Letters.