If you are struggling through the current heatwave, you may be surprised to know that it is not classed as extreme heat – at least according to the Met Office.
In the previous heatwave in June, the Met Office issued “red” warnings of extreme heat for London and the Home Counties, when temperatures were only a few degrees higher than they are now.
Forecasts in June were that some areas could reach 40°C and at times feel higher, although in the end, the highest temperature recorded was 37°C, in Norfolk.
This time round, temperatures have reached 34-35°C in southern and eastern England, but the Met Office has issued neither its red nor amber warning.
On the other hand, heat warnings have been issued by the UK Health Security Agency (UKHSA), whose focus is health and any impacts on the NHS and social services.
It has issued an amber heat health alert for the East Midlands, West Midlands, East of England, London, South East, South West, Yorkshire and the Humber and the North West, from Friday to Sunday. In the North East a yellow warning is in place, one level down.
These warnings mean that health risks have increased, particularly for vulnerable groups.
A dry Greenwich Park in south-east London on Friday. The UK Health Security Agency has issued heat health alerts for most of England this weekend (Photo: Carl Court/Getty)
“We don’t currently expect the health impacts to be as high as the heatwave we saw at the end of June but older adults and those with pre-existing conditions are still at risk,” said Agostinho Moreira de Sousa, head of extreme events and health protection at the agency.
Why the Met Office differs
So, why haven’t the Met Office’s extreme weather warnings kicked in? That’s because, rather than just health, the agency weighs up a wider range of impacts from the heat, including risks to infrastructure, transport and other essential services, said a spokesperson.
And Met Office warnings are based on not only the peak daytime temperature, but also overnight temperatures, humidity, the duration of the heatwave and how unusual the conditions are for the time of year.
“The June heatwave resulted in extreme heat warnings because of a combination of very high temperatures, exceptionally warm overnight conditions and high humidity, all of which were expected to lead to significant impacts,” said the spokesperson.
“While the current heatwave is bringing very warm conditions, the forecast impacts are currently considered lower than during the June event,” they said. “Humidity levels are lower and there is likely to be more overnight relief from the heat. As a result, the heat is expected to place less sustained stress on people, infrastructure and services.”
Spectators seek shade on as they watch the men’s singles quarter-final between Arthur Fery and Alexander Zverev at Wimbledon (Photo:: Adam Davy/PA)
However, the current heatwave may start placing more strain on people because of its persistence, warned Professor Andrew Charlton-Perez, a meteorologist at the University of Reading.
While Thursday and Friday are thought to have been the peak of the high temperatures, it is still forecast to be warmer than average into next week. While the east of England will start cooling, the warmer temperatures will spread west into Wales and Ireland.
That means this summer could beat the record-breaking summer of 1976 for the most number of days with temperatures over 30°C, said Charlton-Perez.
“Psychologically, that 30-degree threshold is an important one,” he said. “And we are well on our way to meeting and passing the number of 30-degree days that happened in 1976.”
So far this year, there have been 12 days where the Reading University Atmospheric Observatory has recorded temperatures of 30°C or more. In 1976 there were 14 such days.
Also, for the first time ever, six separate days of 35°C or higher have been recorded, beating the previous record of five days, seen in 1976 and 2020.