The Amber warning, which has been issued for Sunday, Monday and now Tuesday, highlights likely adverse health effects for the public, not just limited to those most vulnerable to extreme heat. Temperatures could peak in excess of 35C in the southeast, and more widely around 32C within the warning area, with Monday and Tuesday most likely to see temperatures around this level.  

The Amber warning comes at the end of a week when the UK will see widely-above average temperatures, with little relief from the heat at night. A Level 3 UK Health Security Agency Heat Health Alert has also been issued 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 today and 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, evenings and nights then a little cooler than earlier this week. During the weekend, 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 still see temperatures in excess of 25C in a few places, well above their average for the time of year.  

Met Office Deputy Chief Meteorologist Dan Harris 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 warm weather looks likely to steadily ramp up once again this weekend, probably peaking early next week. 

“From Sunday, but more likely Monday, peak maximum temperatures could be in excess of 35C, most likely central and southeast England. Elsewhere, maxima will generally range from high 20s to low 30s of Celsius. This, coupled with overnight minima not falling below 20C in many locations, has considerable potential to cause widespread societal impacts, which is behind the issuance, and subsequent extension, 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.” 

RAC Breakdown spokesman Rod Dennis said: “An amber warning for extreme heat over such a wide area is rare and as a result we strongly urge drivers in England and Wales to think carefully before they drive, and do everything they can to avoid a breakdown. This starts with checking the coolant and oil levels under the bonnet when the engine is cold. Oil should be topped up if it’s low, and if coolant isn’t between the ‘min’ and ‘max’ levels then drivers should top it up – or take it to a reputable garage to get it checked without delay. 

“Anyone who has to take to the roads in these temperatures should ensure they carry plenty of water with them and an additional camping-style water carrier is a good idea so they can top up as needed, and keep their passengers as cool and comfortable as possible too. Starting journeys early in the morning or later in the evening is also a good idea, to avoid the hottest parts of the day.” 

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 38.7C, which was reached at Cambridge Botanic Garden on 25 July 2019.  

The Met Office’s Dan Harris 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 in next 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 40C in parts of the UK over the coming weekend and beyond. These have highlighted the potential which exists in the developing weather situation, but recent evidence suggests the chances have decreased. That said, it’s still a few days away, and there is still time for reversal of this trend.  Mid, to possibly locally high, 30s remains more likely.” 

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.”