50-50 chance UK will see another 40°C day in 12 years, Met Office says

In July 2022, people in the UK were caught off guard. The country experienced its first recorded temperature above 40°C on 19 July, when the mercury climbed to a high of 40.3°C at Coningsby in Lincolnshire.

There’s still a “remember where you were when” quality to the baking hot air that day. But summer 2022’s intense heatwave should not be dismissed as an isolated occurrence, according to a new report from the Met Office.

Due to climate change, there is now a 50-50 chance of seeing another 40°C day in the next 12 years, scientists at the national weather and climate service say.

"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,” says Dr Gillian Kay, senior scientist at the Met Office and lead author of the report published in the journal Weather.

“Because our climate continues to warm, we can expect the chance to keep rising.”

Will the UK have a heatwave this week?

The research comes as the UK Health Security Agency, in conjunction with the Met Office, has issued a yellow heat health alert - the second of 2025 - for numerous regions across England this week.

In an alert system ranging from green to red, a yellow alert means that the heat could be a health risk for vulnerable people. The warning is in place from midday today until 6pm on Sunday 22 June in the Midlands, South and East England, Yorkshire and Humber, and London.

A heatwave is declared when a region reaches a particular temperature threshold, which varies from 28°C in the south to 25°C up north, and stays there for three days in a row. With temperatures forecast to climb to 31°C in London tomorrow, for example, the classification of this hot stretch as a heatwave is looking very likely. 

Unusually hot weather is widespread across Europe this week, with Spain on the frontline as temperatures soar to 40°C in Seville and surrounding areas. Parts of Germany, Switzerland and France are feeling the heat too; Paris is set to be 35°C on Saturday, according to the forecast from Weather & Radar.

Meteorologist Lars Lowinski tells Euronews Green this “is part of an increasing trend of hot spells developing earlier during the season while also becoming more intense/longer-lasting, something that can clearly be attributed to climate change.” 

How hot can the UK get?

For now, 2022 remains Europe’s hottest summer on record. It brought significant impacts in the UK, including wildfires, disruptions to transport and power systems, and increased heat mortality. 

The UK Health Security Agency (UKHSA) reported close to 3,000 heat-related excess deaths in England over that summer. During four days around the peak of the heatwave, from 17–20 July, there were over 1,000 excess deaths in the most vulnerable age group of over 65-year-olds.

But the Met Office’s new report found that temperatures several degrees higher than those seen in July 2022 are possible in today’s climate. 

A maximum of 46.6°C is plausible, according to the scientists’ modelling.

UK heatwaves are getting longer as well as hotter

The study also finds that heatwaves are getting longer as climate change ramps up. 

Older generations might recall the hot summer of 1976, which had more than a fortnight above 28°C. 

In today’s climate, such conditions could persist for a month or more, says Dr Nick Dunstone, Met Office science fellow and co-author of the study. 

“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."  

How is the UK adapting to heatwaves?

The UK is waking up to the dangers of increasing heat under climate change. 

The UKHSA’s heat-health alert system has been in place since 2004, following the deadly 2003 heatwave across Europe. It operates as an early warning system for the health and social care professionals, as well as the voluntary and community sector and government departments. 

As a more direct way of reaching the public, the Met Office also issues extreme heat warnings. 

A simple ‘beat the heat’ guide from the government highlights the risk of heat exhaustion and heatstroke in hot weather. It features reminders to stay in the shade during the middle of the day, stay hydrated, wear sunscreen, and even - as a way to stay cool - eat ice lollies. 

Published in April this year, a more complex Climate Adaptation Research and Innovation Framework from the government sets out the need for improved understanding of climate extremes and tools for stress testing across key sectors.

On the topic of health, it calls for more research and innovation in a number of areas, including, safe working temperatures in classrooms, energy-efficient ways to adapt to heat stress, such as passive building designs, and exploring the use of AI to assist public health workers. 

Other European countries are exploring solutions too. In France, for example, more green spaces and white roofs have been suggested as ways to help the capital cope with potential 50°C heat in the future.