Thunderstorms are bringing the UK’s September heatwave to an end following seven consecutive days of 30°C temperatures.
The weekend saw parks and beaches packed as Britons looked to enjoy the last of the summer sun after a run of high temperatures which saw the UK record seven consecutive days of 30°C in September for the first time ever.
Cambridge was the hottest place in the UK on Sunday, with thermometers hitting 32.5°C, just 0.2°C below Saturday’s 32.7°C temperatures recorded at Heathrow.
Saturday’s scorching heat saw September post the hottest day of the year for only the third time in seven decades. However, 2023’s record looks set to remain well below the 40.3°C recorded on 19 July last year.
Met Office forecaster Tom Morgan said the seven-day heatwave had been “unprecedented”. He added: “We have never seen anything as long-lived in terms of a heatwave in September before.”
But as the heatwave drew to a close, thunderstorms hit much of the north of England, Scotland and Northern Ireland on Sunday after yellow weather warnings were put in place by the Met Office.
While temperatures are predicted to return to milder highs of around 21°C by the end of this week, the Met Office said there was a chance of high pressure towards the end of September and the start of October which could see temperatures return to above-average levels.
The unseasonal heatwave was caused by an area of high pressure to the southeast of the UK and a tropical cyclone season in the North Atlantic which pushed to the jet stream well to the north of Scotland, allowing warm air to be drawn north.
The Met Office has said such weather events will become more frequent as the climate changes, with the chance of hot spells exceeding 30°C for two days or more becoming 16 times more likely by 2070 than it is today.
Met Office Principal Fellow for Climate Extremes, Paul Davies, added: “As our climate warms we know that we will see more frequent and more severe hot spells, and we’re starting to see the increase in frequency already.”
The heatwave came in the same week that Europe’s Copernicus Climate Change Service confirmed that globally, the June-August period had been the hottest on record.
The global average temperature was 16.77°C, 0.66°C above the norm. The European average for summer was 19.63°C, which at 0.83°C above average, was the fifth warmest on record.
Professor David Reay, executive director of the Edinburgh Climate Change Institute, University of Edinburgh, said of the Copernicus findings: “Even those still with their heads in the sand on climate action must now be wondering why their bums are so very hot.”