Photo by Francesco Ungaro
The UK has a 50% probability of experiencing temperatures soaring to 40°C again within the next 12 years, according to the latest analysis by the Met Office. The warning comes as the risk of extreme heat continues to rise in the face of the escalating climate emergency.
In a sobering update, the UK’s national weather service also stated that even higher temperatures — reaching 45°C (113°F) or more — are now “plausible” under today’s climate conditions. Additionally, the length and severity of heatwaves are also expected to increase, potentially stretching beyond a month.
The UK first breached the 40°C mark during the unprecedented heatwave of summer 2022. Temperatures peaked at 40.3°C in Coningsby, Lincolnshire on 19 July, eclipsing the previous national high of 38.7°C recorded in Cambridge in 2019. The blistering heatwave was accompanied by widespread drought, leading to catastrophic wildfires across the country. Fire brigades in London, Leicestershire, and South Yorkshire declared major incidents as flames engulfed homes, schools, churches, and farmland. The searing temperatures also caused major disruptions across transport and power networks.
The human toll was equally grim. More than 1,000 excess deaths were recorded among older adults around the peak four days of the 2022 heatwave, while over 3,000 people in England are believed to have died as a result of heat-related causes over the entire summer.
The Met Office’s latest projections stem from new modelling studies using large-scale global climate simulations that estimate how frequently extreme temperatures could occur in today’s climate. The research, published in the journal Weather, shows a staggering increase in the likelihood of 40°C days in the UK. Compared to the 1960s, such events are now more than 20 times more probable, and the risk has nearly tripled since the year 2000.
With the planet continuing to warm due to greenhouse gas emissions, the likelihood of record-breaking heat is expected to rise even further. Based on current climate trends, the Met Office estimates that there is a 50/50 chance the UK will see at least one day hitting 40°C again within the next dozen years.
Even more concerning is the potential for future temperatures to exceed those recorded in 2022. The modelling suggests that a maximum of 46.6°C could be within the realm of possibility in the current climate, making the 2022 heatwave a potential harbinger of worse to come.
“The chance of exceeding 40°C has been rapidly increasing, and it is now over 20 times more likely than it was in the 1960s,” explained Dr Gillian Kay, senior scientist at the Met Office and lead author of the study. “Because our climate continues to warm, we can expect the chance to keep rising. We estimate a 50/50 chance of seeing a 40°C day again in the next 12 years. We also found that temperatures several degrees higher than we saw in July 2022 are possible in today’s climate.”
The study didn’t just stop at maximum temperatures — it also examined the projected intensity and duration of heatwaves. Results indicate that under current climate conditions, far more extreme and prolonged heatwaves could strike the UK.
For example, up to two-thirds of summer days in south-east England could surpass the 28°C threshold that defines a heatwave in that region. The model further predicts that a heatwave lasting more than a month is not only possible, but increasingly likely. Additionally, periods with 12 consecutive days of 35°C temperatures could also occur — a prospect that would stretch infrastructure, emergency services, and public health systems to their limits.
Dr Nick Dunstone, Met Office science fellow and co-author of the study, cited historical data to put these projections into context. “The well-known hot summer of 1976 had more than a fortnight above 28°C, which is a key heatwave threshold in south-east England,” he said. “Our study finds that in today’s climate such conditions could persist for a month or more. These findings highlight the need to prepare and plan for the impacts of rising temperatures now, so we can better protect public health, infrastructure and the environment from the growing threat of extreme heat.”
The findings underscore the increasing urgency for climate adaptation and resilience planning. With the UK already experiencing record-shattering temperatures, scientists and officials alike warn that the future may bring even more extreme weather unless aggressive mitigation and adaptation strategies are enacted swiftly.
