A new record: The 10 hottest temperatures in UK history

Montage image of a parasol on the beach, a thermometer reading 40, and cars driving on a sunny motorway
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As the UK faced its hottest temperatures on record in July 2022, the warmer weather sparked more and more conversations about environmental issues. Seven of the ten hottest temperatures in UK history have been recorded since 2003 which could be a sign of continued global warming. Though the summer of 1976 was also a scorcher.

There’s one thing for certain though, we Brits are not designed to handle the heat. Many of us will spend the summer months refreshing our ‘Met Office’ weather apps and feeling slightly sick while looking at the numbers flash up in red.


How was the Met Office founded?

The Meteorological Office, known as the Met Office for short, is the UK’s national weather service and was founded in 1854. The original purpose of the organisation was to learn more about marine climatology and improve the safety of men at sea.

Its creator, Vice-Admiral Robert FitzRoy, gained notoriety as captain of the HMS Beagle for Charles Darwin’s most famous trip. FitzRoy started to make daily weather predictions and forecasts to warn sailors and fishermen about potentially deadly storms. He was inspired to do so after the Royal Charter, a passenger vessel, was wrecked in October 1859, resulting in 459 lives being lost.

In 1861, FitzRoy knew that average citizens were also interested in his forecasts, so he started to make them public. While their needs were not quite as life-or-death as the sailors, it was useful to know when they could go for a walk or hang the washing out.

How does the Met Office make weather forecasts?

The Met Office’s forecasting methods have changed somewhat over the past century or so. The very first predictions were made using 15 land stations positioned around the UK. They would telegraph weather reports at set times to help make forecasts for other areas.

In 1922, Met Office scientist Lewis Fry Richardson published a piece of work that changed the way forecasts were made forever. It laid the foundation for the ‘Numerical Weather Prediction’ method that was refined over decades. Richardson’s work was finally put into practice in 1965, 12 years after his death, when a computer was proficient enough to operate it.

Nowadays the Met Office uses supercomputers to make seamless weather and climate modelling…although they don’t always get their forecasts exactly right.

How are record temperatures measured?

The Met Office holds weather observation records on a digital database for all of its stations dating back to 1853. Every day data points go through quality control, such as checking against nearby stations, to make sure they are accurate. Potential weather records are required to go through rigorous testing and reviewing, which may take several months before they are made official. Records may also be reviewed at a later date as an extra level of quality control.


Hottest temperatures in UK history

The UK’s 2022 heatwave resulted in some exceptionally high temperatures that smashed previous records. Here are the 10 hottest temperatures in UK history:

  1. 40.3°C - Coningsby, Lincolnshire - 19 July 2022
  2. 38.7°C – Cambridge Botanic Gardens, Cambridgeshire – 25 July 2019
  3. 38.5°C – Faversham, Kent – 10 August 2003
  4. 37.8°C – Heathrow, London – 31 July 2020
  5. 37.1°C – Cheltenham, Gloucestershire – 3 August 1990
  6. 36.7°C – Heathrow, London – 1 July 2015
  7. 36.7°C – Raunds, Northamptonshire – 9 August 1911
  8. 36.6°C – Worcester, Worcestershire – 2 August 1990
  9. 36.5°C – Wisley, Surrey – 19 July 2006
  10. 36.4°C – Kew Gardens and Heathrow, London – 7 August 2020

None of the 10 hottest UK temperatures have been reported outside of England. However, the 2022 heatwave also resulted in new temperature records for Wales and Scotland. The mercury hit 37.1°C in Hawarden, Flintshire on 18 July 2022 and 34.8°C in Charterhall, Berwickshire on 19 July 2022.

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