Levels of heat never experienced in the UK before will likely be experienced across England and Wales today and tomorrow, with temperatures perhaps reaching 40C. The extreme heat will be short-lived but will hit hard for everyone.
On Sunday, the highest temperature reached 33.0C at Hawarden in northeast Wales, making it the hottest day of the year so far in the UK. But this will be beaten by quite a margin over the next few days, as unprecedented extreme heat builds, with the thermometer reaching the high 30s degrees C across large parts of England, potentially reaching 40C for the first time since records began.
The exceptional heat has already gripped Spain, Portugal and France over the past few days, with temperatures reaching 45C in Iberia and temperatures yesterday reaching 40.5C in the Aquitaine region of SW France. The combination of extreme heat and very dry conditions that have built up following a dry Spring and summer so far have led to wildfires to break out across Iberia and SW France.
Plume of extreme heat pushes north over Britain early this week, leading to unprecedented heat never experienced before in the UK
The extreme heat over western France and Iberia over the weekend will spread north across the UK today and tomorrow, as high pressure that been over the UK shifts east and combines with low pressure to the southwest to pull in a very hot southerly flow from France. So, under mostly clear skies also spreading north, temperatures across large parts England and Wales are forecast to reach the high 30s degrees C, perhaps 40-41C in a few spots across central and eastern England – this more likely tomorrow. The UK’s highest temperature ever recorded currently stands at 38.7C reached on the 25th July 2019 at Cambridge Botanic Gardens. This record is highly likely to be smashed by quite a margin. Previous to the new temperature record made in 2019, the record was 38.5C in August 2003, prior to that, the record was set at 37.1C in 1990.
Yesterday evening and overnight saw some scattered heavy showers with thunder across SW and central southern England, these weren’t well forecasts by most media forecasts, but we do often see elevated storms develop on the leading edge of hot plumes moving north in summer. Not much of the rain reached the ground, so barely settling the dust for most that caught them. The plume of hot air has now arrived in the south, along with clearer skies, from western France and it’s very warm air to quite a height in the atmosphere, model forecasts bring 850 hPa temperatures, or around 1,500 metres up, reaching 24-25C tonight, add 10-15C on for surface temperatures during the day.
It’s a warm start to Monday morning, temperatures already 20-21C at 6am across North and West Yorkshire, high teens widely elsewhere across England. But temperatures will rapidly rise in the sunshine through the morning and the afternoon, reaching 35-39C across inland England and Wales south of a line between Liverpool and Hull, high twenties to low 30s C across the far north of England. Southern Scotland and N. Ireland look set to reach the high 20s Celsius, perhaps 30C in one or two spots. Cooler around coasts with onshore breezes developing. Not only is the current UK’s highest temperature of 38.7C set in 2019 under threat today, also national records are likely to be broken.
An exceptionally warm night to come tonight across England and Wales, with highest night time minima records likely to be broken, the record currently stands at 23.9C set in Brighton on 4th August 1990. Tonight some models show temperatures of 27C at 3am in NW England, so the record is likely to go somewhere.
Then we do it all again on Tuesday, perhaps a degree or two hotter still, with a strong chance that 40C will be breached for the first time ever, and perhaps not in just one location. This beats the previous record by some margin, the difference between the August 2003 record set and then the new record in July 2019, was just some 0.2C, tomorrow could beat the 2019 record by a few degrees! Relief will be on the way though in the west, as a cold front moves in, this will bring some thundery showers across SW England and Wales during the afternoon – before pushing toward SE England in the evening. Some showery rain, perhaps heavy and thundery, pushing in across N. Ireland then western and northern Scotland through the afternoon too.
But the extreme heat will hold on until late for much of England on Tuesday. A Met Office red warning for extreme heat is now in place across a central swathe of England including large urban areas of London, Birmingham, Manchester, Leeds, Sheffield, Nottingham and Leicester. The rest of England, Wales and also southern Scotland, including Edinburgh, is under an amber warning. The extremely high temperatures by day and tropical night temperatures not falling below 20C at night across many areas of England and Wales is dangerous to health for even healthy people. The main precautions to take are to keep hydrated, stay out of the sun, especially during the peak of the day, avoid physical exertion and keep an eye on elderly and vulnerable people.
Relief on the way Tuesday night, as cold front moves in from the SW, bringing cooler air, temperatures return more towards average rest of the week, with a risk of showers in places.
Thankfully the extreme heat will be fairly short-lived, with a cold front moving in from the southwest later tomorrow and through Wednesday morning, as low pressure moves northeast across the UK. This cold front will sweep the hot plume away eastwards and introducing somewhat cooler and more comfortable temperatures for most for the rest of the week, though it could still reach 30C in the SE of England on Wednesday – but this is a big drop on the next few days! Wednesday is likely to some scattered showers – more especially across England and Wales – where they could be heavy and thundery towards the east. Thursday and Friday will see temperatures closer to average for most places, with a mixture cloud, sunny spells and some showers, showers more widespread on Friday.