Weather maps show a 700 mile-wide plume of tropical air moving towards Britain, with temperatures likely to rise above 86F, making Thursday the hottest day of the year so far – beating May 20, when the mercury hit 82F (28.2C) in Suffolk.
Met Office forecaster Marco Petagna said: “34C looks a distinct possibility on Thursday.” Weather Outlook forecaster Brian Gaze added: “June has been flaming wet, but will switch to flaming hot.”
Sunlight includes ultraviolet radiation which damages the DNA of viruses. Viruses tend to survive better in cold weather because they have a fatty protective coating which degrades when it is warm. While the melting of the coating allows the virus to invade the warmth of the body, it dies if the casing disintegrates outside.
A new study from the US National Biodefense Analysis and Countermeasures Center also found that coronavirus floating in the air decays by 90 per cent in just six minutes of summer sunshine and 19 minutes of winter sunlight.
During the Spanish Flu pandemic of 1918, doctors noticed that patients who were nursed outdoors appeared to fare better.
High temperatures may also play a role. One study by Harvard University showed that at 43F (6C) in dry weather, flu survived on a surface for more than 23 hours, but at a temperature of 90F (32C) it was dying within an hour.
Bright sunlight can quickly heat up surfaces beyond 90F (32C) even if the outside air temperature is lower.
Britain experienced the sunniest April on record, which has coincided with a substantial fall in new cases. The UK had an average of 224.5 hours of sunshine, compared with 211.9 hours in April 2015, the previous highest.
Researcher Dr Richard Hobday, author of The Healing Sun and The Light Revolution, said: “Sunlight was used on critically ill influenza patients during the 1918 pandemic. This reduced deaths from 40 per cent to 13 per cent.
“The finding that sunlight kills the virus in aerosols could be significant.”
The University of Oxford also recently conducted a review into whether climate conditions were playing a role in the transmission of coronavirus, also found that cold and dry conditions appear to boost spread.