UK drivers have been warned that they face many unbearable summers on the road if they do not make one change to their cars. Scientists recently published a study in the City and Environment Interactions journal focusing on the rising temperatures across Europe and how drivers are being impacted.
Several cities across the continent have seen temperatures surge to 40°C, with the UK experiencing four heatwaves in 2025 already and the Met Office predicting that this summer will ‘almost certainly’ be the warmest on record. The study found that the colour of your car can not only turn your vehicle into a furnace, but also contribute to the entire neighbourhood heating up. Dark-coloured vehicles release much more heat than lighter ones, raising nearby air temperatures by several degrees, as the study, by the University of Lisbon, found that a black car raised nearby air temperatures by up to 3.8°C, while a white car had a much smaller effect.
Dr Márcia Matias and colleagues conducted the study and suggested that the urban heat island effect, a phenomenon where cities become significantly warmer than their surrounding rural areas due to human-made materials that absorb and retain heat, could be significantly boosted by vehicle colour.
“Now picture thousands of cars parked across a city, each one acting like a little heat source or a heat shield,” Dr Matias explained, adding, “Their colour can actually shift how hot the streets feel.”
The researcher suggests fleets of taxis, delivery vans or other vehicles adopting lighter shades of paint to help reduce the effect.
A 2022 study, published by JRC Publications Repository, proposed that cities were sometimes up to 10-15°C hotter compared to more rural areas on the same day.
As roughly 80% of Brits live in urban areas, Dr Matias worries the urban heat island effect could become a pressing public health concern across the UK and Europe.
Another study found that around 1,500 people, across 12 European cities, were killed by human-caused climate change during 2024 heatwaves in June and July, according to scientists at Imperial College London and the London School of Hygiene & Tropical Medicine.
But, efforts are being made by some cities to counteract the damage caused by intensifying heat, such as Barcelona, which has introduced designated climate shelters - public buildings including schools, libraries or museums, provide respite from the sun for residents during heatwaves.
Dr Matias and fellow researchers believe that repainting dark cars in Lisbon to lighter shades could double the reflectivity of certain streets from around 20% to around 40%, lowering near-surface air temperatures on hotter days.
Climate researcher at the University of North Carolina, Sarah Berk added that “Vehicles are a surprisingly overlooked piece of the urban heat puzzle,” noting that more time is spent researching how to utilise reflective roofs or lighter pavements.
