Britain’s Met Office on Friday issued the first ever “red” warning for large parts of England as temperatures are expected to reach 40 Celsius (104 Fahrenheit) for the first time early next week, posing a risk of serious illness and even death among healthy people. The warning covers Monday and Tuesday.

“We hoped we wouldn’t get to this situation but for the first time ever we are forecasting greater than 40°C in the UK,” said Nikos Christidis, a Met Office scientist.

“In a recent study we found that the likelihood of extremely hot days in the U.K. has been increasing and will continue to do so during the course of the century, with the most extreme temperatures expected to be observed in the southeast of England.”

Also Read: Officials declare national emergency for the United Kingdom over severe heatwave

Why is the UK experiencing a heatwave?

The most important factor is the ‘Azores High’ subtropical pressure system. It typically rests off the coast of Spain but has developed and moved further north, bringing high temperatures to the UK, France, and the Iberian peninsula. 

According to Annie Shuttleworth at the Met Office, the UK will witness a slight cooling in the middle of the week as cooler air descends from the north. However, southern England will continue to experience temperatures in the high 20s.

The second factor is the winds blowing hot air up from north Africa and the Sahara.

“At the end of the week, temperatures will be close to 40C (104F) to 45C across France and Spain and when we get a southerly wind, the UK will then tap into some of that heat,” said Shuttleworth, The Guardian reported. 

High temperature is the ongoing impact of climate change. Scientists claim that heatwaves are becoming more intense due to human-caused global heating.

“When it comes to summer heat, climate change is a complete gamechanger and has already turned what would once have been called exceptional heat into very frequent summer conditions,” said Dr Friederike Otto, of Imperial College London.

“Every heatwave we experience today has been made hotter because of the fossil fuels we have burned over the last decades in particular.”