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UK heatwave 2020 11 September 2020

Met Office: The UK’s record–breaking August 2020 heatwave (via Carbon Brief)

As the UK moves into autumn, it offers the opportunity to look back at the pronounced, record–breaking heatwave that hit the southeast of the country during August.

Early August saw a long run of days with temperatures somewhere reaching 34C, along with several “tropical nights” where nighttime temperatures did not drop below 20C.

Nearby countries in Europe also faced extreme heat, before the hot spell ended with thunderstorms and torrential downpours leading to widespread disruption including flooding.

In this article, we look back on the recent heatwave and the factors that contributed to it. 

A record–breaking hot spell

After a relatively cool July, which was around 0.8C colder than the long–term (1981–2010) average, the first signs of the heatwave were seen on the last day of the month. This was later confirmed as the third–hottest day on record in the UK, with a temperature of 37.8C at Heathrow.

This isolated hot day turned out to be the prelude to a much longer heatwave, which began the following week on 7 August, during which many areas of the southeast saw six consecutive days of well–above average temperatures.

Heatwave conditions in a particular location are defined by the Met Office as a period of at least three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold. As the right–hand map below shows, this heatwave temperature threshold varies throughout the country and is higher towards the southeast. 

Read the full story here…