Temperatures of 40C will become norm for British summers, leading meteorologists warn

·6-min read
A rainbow appears over flooded fields in the Wye Valley, near the hamlet of Wellesley, following Storm Dennis on February 17, 2020 in Hereford - Christopher Furlong/Getty Images
A rainbow appears over flooded fields in the Wye Valley, near the hamlet of Wellesley, following Storm Dennis on February 17, 2020 in Hereford - Christopher Furlong/Getty Images

British summers are likely to regularly see temperatures of above 40C even if humanity manages to limit global warming to 1.5C, the UK's leading meteorologists have warned.

The UK is already seeing increasingly extreme weather, with 2020 the third warmest, fifth wettest and eighth sunniest year on record - the first ever to fall into the top 10 for all three variables.

Data published in the report The State Of The UK Climate 2020 revealed the average winter temperature for last year was 5.3C - 1.6C higher than the 1981 to 2010 average.

That makes December 2019 to February 2020 the fifth warmest winter on record, while the temperature last summer was 0.4C above average at 14.8C.

Early August 2020 saw temperatures hit 34C on six consecutive days, with five "tropical nights" where the mercury did not drop below 20C, making it one of the most significant heatwaves to affect southern England in the past 60 years, the report's authors said.

Mike Kendon, climate scientist at the Met Office and lead author of the report, said the figures indicated a new normal for the UK.

Mr Kendon warned man-made global warming will last "for a very, very long time to come", adding scientists at the Met Office's National Climate Information Centre had been "blown away" by the extreme heat of 49.6C seen on the west coast of Canada in recent weeks.

"An event like that would basically be pretty much impossible without the influence of manmade warming, that's obviously a very severe impact," he said.

Wetter, hotter, sunnier: the data that show UK’s weather is becoming more extreme

Last year was among the wettest, hottest and sunniest years on record, the Met Office has said, as it warned extremes will become more common.

The annual "State of the UK Climate" report found that 2020 was the first year on record which made the top 10 in all three categories of rainfall, sunshine and high temperature.

Published in the Royal Meteorological Society’s International Journal of Climatology, the paper warned that "recent decades have been warmer, wetter and sunnier than the 20th century".

Last year was the third warmest, fifth wettest and eighth sunniest on record for the UK.

Heatwaves and bursts of heavy rain were becoming more common, while snow days were becoming less likely, the paper's authors said, reflecting a warmer climate which can hold more moisture.

A man runs past beach huts along the seafront in Brighton, on the south coast of England on April 10 2020 - GLYN KIRK/AFP via Getty Images
A man runs past beach huts along the seafront in Brighton, on the south coast of England on April 10 2020 - GLYN KIRK/AFP via Getty Images

Lead author Mike Kendon, a senior climate scientist at the Met Office, said: "Our climate is changing, and it is changing now. And that is something that we see clearly in our observations.

"The science is clear that we're going to see more of that, moving into the future."

Last spring was the sunniest on record, included the sunniest April and May, and was also sunnier than most UK summers have been.

Six of the 10 wettest years for the UK have occurred since 1998, and the decade to 2020 was on average nine per cent wetter than the period from 1961 to 1990.

Two of the three wettest days on record happened last year, with Oct 3 seeing the most rainfall in a single day (brought by Storm Alex – see video below) and Feb 15 seeing the third-most. Aug 25 1986 comes second.

Records for rainfall go back to 1862, while those for temperature date to 1884 and sunshine 1919.

A second measure for Central England found 2020 was also the third-warmest year since 1659.

The UK land temperature during the past decade has been 1.1C warmer than 1961-1990, meaning the UK is warming slightly quicker than the global average of 0.8C, the report said.

One positive trend due to the changing climate could be a reduction in extreme snowfall, which can cause flooding as it melts, Mr Kendon added.

An overnight snow fall on Easter Monday in Slayley, Northumberland - Owen Humphreys/PA Wire
An overnight snow fall on Easter Monday in Slayley, Northumberland - Owen Humphreys/PA Wire

The 2018 'Beast from the East', which caused chaos for several days in February and March, would have been a more common event in the past, he said.

"We have had some severe weather relatively recently, like the Beast from the East event in February 2018. But an event like that would have been much more normal in the winters of the 1980s.

"And indeed, we've seen nothing in recent years as severe as January 1963, February 1947. So in general, although we may still get them overall, we'd expect impacts from snow to decline."

The UK had a lot of weather in 2020 ...

It was our third-warmest year

Swimmers in the London borough of Hillingdon on July 31 - Leon Neal/Getty Images
Swimmers in the London borough of Hillingdon on July 31 - Leon Neal/Getty Images

And fifth-warmest winter (December 2019–February 2020), including the sixth-warmest January.

On July 31 a temperature of 37.8C was recorded at Heathrow, making this the UK's third-warmest day on record.

An early August heatwave in southern England was one of the most significant in the past six decades, with days exceeding 34C and nights over 20C.

The fifth-wettest year on record

A man walks his dog under trees reflected in a puddle after rainfall in Greenwich Park, south-east London on October 3, 2020 - JUSTIN TALLIS/AFP via Getty Images
A man walks his dog under trees reflected in a puddle after rainfall in Greenwich Park, south-east London on October 3, 2020 - JUSTIN TALLIS/AFP via Getty Images

Total rainfall in 2020 was 1,336mm, 116 per cent of the 1981-2010 average, making it the wettest year since 2000.

On Aug 16 a rain-gauge in Norfolk recorded a daily total of 239.9mm, the highest ever measured at an individual station in August.

February 2020 was the UK's wettest February and fourth-wettest calendar month on record.

Last year was our eighth-sunniest

Members of the public enjoy the day's warm weather on Primrose Hill on April 5, 2020 in London - Ollie Millington/Getty Images
Members of the public enjoy the day's warm weather on Primrose Hill on April 5, 2020 in London - Ollie Millington/Getty Images

It was the sunniest spring on record, including the sunniest April and May.

The year had 109 per cent of the 1981–2010 average and 113 per cent of 1961–1990 average sunshine hours, with a total of 1,497 hours.

Summer was significantly less sunny than spring, with just three-quarters of the spring sunshine total recorded.

Climate change 'on our doorstep'

Professor Liz Bentley, chief executive of the Royal Meteorological Society, said: "I think sometimes, particularly in the UK, we can become a little bit complacent because we see climate change happening somewhere else or some distance in the future.

"This report clearly is evidence that climate change is already happening and already happening on our doorstep with a number of extremes that are having an impact on us as humans.

"I still find them shocking myself when you see these records being broken, and the frequency with which records are being broken in the UK. It is still a shock to me as a meteorologist, having worked in this area for the last 25 years or so."

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