Extreme heatwaves in May and June are estimated to have caused about 2,700 premature deaths across England and Wales, with scientists attributing more than 40% of those fatalities directly to human-caused climate change. The findings, based on analysis by researchers from the London School of Hygiene and Tropical Medicine and Imperial College London, underscore the growing threat posed by rising global temperatures.
The June heatwave alone killed approximately 440 people per day during its three-day peak, according to the data. For context, about four people die each day in road traffic collisions and roughly 35 per day from alcohol and drug use, based on government statistics. The stark comparison highlights the severity of heat-related mortality, which is being amplified by the climate crisis.
Researchers determined that without the 1.4°C of global heating since pre-industrial times, many of these deaths would not have occurred. The analysis suggests that climate change added between 3°C and 4°C to the temperatures experienced during the heatwaves, making them more intense and prolonged. The Met Office and the World Health Organisation have both warned that such extreme weather events are becoming more frequent and severe as the planet warms.
The May and June heatwaves broke multiple temperature records across the UK, with thermometers soaring well above seasonal norms. In June, temperatures exceeded 30°C in many parts of England and Wales for several consecutive days, placing particular strain on vulnerable populations such as the elderly, those with pre-existing health conditions, and people living in poorly ventilated homes. Hospitals reported increased admissions for heatstroke, dehydration, and respiratory issues during the hot spells.
Public health experts have called for urgent action to mitigate the impacts of extreme heat, including better early warning systems, improved building insulation, and increased access to cooling centres. The analysis also reinforces the need for stronger climate policies to reduce greenhouse gas emissions, which are driving the rise in global temperatures. The UK government has faced criticism from environmental groups for not doing enough to meet its net-zero targets, though officials have pointed to investments in renewable energy and heat pump schemes.
The study adds to a growing body of evidence linking climate change to excess mortality during heatwaves. Previous research has shown that the 2022 European heatwave caused more than 60,000 excess deaths across the continent, with the UK among the worst-affected countries. Scientists warn that without significant emissions reductions, such events will become more common and more deadly in the coming decades.
In response to the findings, campaigners have urged the government to implement a national heat resilience strategy, including mandatory cooling standards for new homes and retrofitting existing buildings. They also called for better public health messaging to help people stay safe during hot weather. The researchers behind the study emphasised that while adaptation measures are crucial, the only long-term solution is to halt global warming by cutting carbon emissions rapidly.
The analysis used statistical models to compare actual death rates during the heatwaves with expected rates based on historical data and temperature trends. By factoring out the influence of climate change, the researchers were able to estimate the number of deaths that would have occurred in a world without human-caused warming. The results provide some of the clearest evidence yet of the direct impact of climate change on public health in the UK.
