August heatwave in East Anglia: How hot is it going to get?

A stunning summer sunset at Sheringham on the Norfolk coast on Wednesday 5 August 2020 Credit: Jan Brown

The final day of July saw the third highest temperature ever reached in the United Kingdom when a thermometer at Heathrow airport peaked at 37.8°C (100°F).

After a brief respite the heat in back and threatening to last into next week in the Eastern Counties.

How hot is it going to get?

Last Friday became the hottest day of the year so far in 2020 in the Anglia region with 35.9°C recorded at Bedford and nudging a little higher in Pitsford in Northamptonshire at 36.1°C.

The Met Office is expecting the maximum temperature on Friday to be somewhere in London or in a corridor northwards towards Cambridge and probably 36-37°C (97-99°F).

Forecasters put the probability of making it to 38°C (100°F) at around 30% while there is only a small chance of beating the all-time temperature record of 38.7°C (101.7°C) set in Cambridge last year.

The UK temperature records for August and for all time. Credit: Met Office

Friday is expected, however, to be the hottest August day since August 2003 when the temperature reached 38.5°C at Faversham in Kent (101.3°F) which had held the UK record until it was beating in Cambridge last July.

Indeed, even getting 35°C or more in August has been rare since then, the closest being on two other occasions in August 2003 and more recently in August 2016 when Faversham again reached 34.1°C (93°F).

The Met Office says there have been only four days in the UK that the maximum temperature has reached 37°C or higher:

  • 31 July 2020

  • 25 July 2019

  • 10 August 2003

  • 3 August 1990

Where is the hot air coming from?

There is a feed a warm air coming off the continent from France and Spain. Temperatures are close to 40°C. The feed of hot air will be briefly interrupted over the weekend before the heat starts to build again into next week.

How long will it last?

What could also be remarkable about this heatwave is how long it lasts - temperatures in many places are expected to rise about 30°C until Tuesday with some sultry nights in between.

The Jet Stream is a fast moving ribbon of air that drives weather systems towards us when we are close to it and away from us when it it not near the UK.

The Jet Stream is very weak at the moment and dipping down into the southern Atlantic before pushing northwards and dragging hot and humid air with it from Spain and France.

The Jet Stream will slowly change position, cutting off the source of the hot air through Wednesday and Thursday.

Getting three days in a row with a maximum temperature at 35°C or higher in the UK is also rare - it has happened only three times since 1960.

It occurred twice during the famous heatwave of 1976 - in June and July - and then again in early August 1990.

A golden sunset on the Norfolk coast as the region prepare for a heatwave. Credit: Dave Bradley

Looking at the month as a whole and taking daytime highs and night time lows into account, the hottest August on record in East Anglia was in 1997 and before that as far back at 1911.

Last August was the joint tenth hottest August on record in the region along with 2016. In 2019, the highest official temperature achieved in the Anglia region was 32.6°C (90.7°F) recorded in Cambridge and nearby Sawtry.