(The Express) Meteorologists have said a key factor is that the jet stream, which keeps air flowing round the the northern hemisphere at altitudes of about just under four miles has been “stalled” over Europe for the last two months.

As a result, regions of high pressure have been trapped which are cloudless, windless and very hot.

Jennifer Francis of Rutgers University in New Jersey said: “It’s been a key player in the astounding heatwaves across the UK and Scandinavia this summer.”