An Amber Extreme heat warning, which is an impact-based warning designed to highlight impacts to protect lives, property and infrastructure, has been issued for Sunday, Monday and Tuesday. 

Temperatures are likely to peak in excess of 35°C in southern, central and eastern areas of England, and more widely around 32°C within the warning area. Tuesday currently looks to see the peak of this heat, although exceptional warmth is likely throughout the warning period.  

Temperatures are also set to remain high overnight, particularly in urban areas, with a high likelihood of tropical nights – when minimum temperatures don’t drop below 20°C – for some early next week.  

A Level 3 UK Health Security Agency Heat Health Alert, which is aimed at those specifically in the health and social care sector, has also been issued by the from Saturday to Tuesday, advising people to look out for vulnerable people and those with underlying health conditions.  

Heatwave criteria, when specific temperature thresholds must be exceeded three days running, had already been met in some locations earlier this week, and are expected to be met again by early next week. This is most likely across England and Wales, but also fairly likely for eastern Scotland too. 

Warming up

Warm summer conditions will remain in place for much of the week for the majority of England and Wales, albeit slightly less hot on Thursday, when temperatures are more likely to peak in the mid-20s Celsius for many.  

High pressure near the southern half of the UK is responsible for this week’s warm spell and builds back into the UK for Thursday, bringing largely dry and clear weather for many for the rest of this week. During the weekend, a developing southerly flow will allow very high temperatures currently building over the continent to start to spread northwards into the UK. Further north, eastern areas of Scotland could see temperatures in excess of 25°C in a few places, well above their average for the time of year.  

Met Office Deputy Chief Meteorologist Tony Wardle said: “Maximum temperatures have been well above average almost everywhere in the UK this week, the exception perhaps being the Western and Northern Isles of Scotland. Following a return to nearer average, locally rather cool temperatures over the next few days, the hot weather looks likely to steadily ramp up once again this weekend, peaking early next week. 

“From Sunday, but more likely Monday and Tuesday, peak maximum temperatures are likely be in excess of 35°C, especially across central, southern and eastern England, with a chance of some locations being even hotter. Elsewhere, maxima will generally range from high 20s to low 30s of Celsius. This, coupled with overnight minima not falling below 20°C in many locations, has considerable potential to cause widespread societal impacts, which is behind the issue of an Amber Extreme heat warning.” 

Dr Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, said: “Heat-health alerts have now been issued to the majority of the country, with temperatures set to remain consistently high throughout the duration of this week. 

“Most of us can enjoy the hot weather when it arrives, but it is important to keep yourself hydrated and to find shade where possible when UV rays are strongest, between 11am and 3pm. 

“If you have vulnerable family, friends and neighbours, make sure they are aware of how they can keep themselves protected from the warm weather.’’  

Advice

Peter Jenkins, Director of Campaigns, Water UK said: “Water companies are seeing substantial demand during this extremely hot weather. We can all help ensure there’s enough to go around by being mindful of the amount of water we use while ensuring we stay hydrated and safe. 

“By making just small changes indoors or in the garden you can have a big impact on our water consumption. Our Water’s Worth Saving campaign has a host of helpful top-tips showing the simple things we can all do to save this precious resource, so it remains readily available now and in the future.” 

Mel Clarke, Customer Service Director for Operations at National Highways, said: “It is always important to plan ahead for your journey and this advice is no different during periods of hot weather. Our advice is that everyone should check their vehicles, such as tyres, coolant and oil levels, before heading out.” 

Find out more about driving in hot weather with National Highways.  

Government advice is that 999 services should be used in emergencies only; seek advice from 111 if you need non-emergency health advice. 

Top ways to stay safe when the heat arrives are to: 

  • Look out for those who may struggle to keep themselves cool and hydrated. Older people, those with underlying conditions and those who live alone are particularly at risk. 

  • If you live alone, ask a relative or friend to phone to check that you are not having difficulties during periods of extreme heat. 

  • Stay cool indoors: Close curtains on rooms that face the sun to keep indoor spaces cooler and remember it may be cooler outdoors than indoors. 

  • If going outdoors, use cool spaces considerately.  

  • Drink plenty of fluids and avoid excess alcohol.  

  • Never leave anyone in a closed, parked vehicle, especially infants, young children or animals. 

  • Try to keep out of the sun between 11am to 3pm, when the UV rays are strongest. 

  • Walk in the shade, apply sunscreen and wear a wide-brimmed hat, if you have to go out in the heat. 

  • Avoid physical exertion in the hottest parts of the day. 

  • Make sure you take water with you, if you are travelling. 

  • Check the latest weather forecast and temperature warnings – you can find these on TV, radio, mobile app or website. 

  • During warm weather going for a swim can provide much welcomed relief. If you are going into open water to cool down, take care and follow local safety advice. 

Will we get record-breaking heat?

The record high temperature in the UK is 38.7°C, which was reached at Cambridge Botanic Garden on 25 July 2019.  

The Met Office’s Tony Wardle added: “Weather forecast models are run numerous times to help us quantify the likelihood of a particular event occurring and estimate the uncertainty which is always present in weather forecasting to some degree. For late this weekend and especially early next week, some runs of these models continue to allow exceptionally high temperatures to develop, which is something we’ll keep monitoring closely and adding details in the coming days as confidence increases. 

“Some models had been producing maximum temperatures in excess of 40°C in parts of the UK over the coming weekend and beyond. These have highlighted the potential which exists in the developing weather situation, but it’s as yet uncertain if these values will materialise. Mid, to possibly locally high, 30s Celsius remains the most likely scenario.” 

Climate change

Whilst a 1°C background temperature increase may not seem significant, the resulting increase in the severity of extreme heat events is already evident in the observed record. This has widespread and significant impacts. 

Extreme heat events do occur within natural climate variation due to changes in global weather patterns. However, the increase in the frequency, duration, and intensity of these events over recent decades is clearly linked to the observed warming of the planet and can be attributed to human activity. 

Dr Mark McCarthy is the head of the Met Office National Climate Information Centre. He said: “The highest temperatures experienced in the UK tend to occur when our weather is influenced by air masses from continental Europe or North Africa – as it will be at the weekend - there is already a strongly-embedded warming due to climate change across the continent, that is increasing the likelihood of challenging the existing UK temperature record.”