WIREDGOV

Official heatwave criteria will be met for large parts of southern UK this week, with temperatures likely to remain high into the weekend for much of England and Wales.

Temperatures are on the rise for much of the UK, likely peaking on Wednesday and Thursday with 32°C likely across parts of the south and southeast, though there’s an increasing signal for a thundery breakdown for some.

There’s a chance the highest temperature of the year so far of 32.2°C on 10 June could be exceeded this week, most likely in the southeast where one or two places could see 33°C.  

Met Office Chief Meteorologist Neil Armstrong said:

“High pressure is situated to the southeast of the UK, which is bringing more settled conditions and temperatures well above average for the time of year. While the highest temperatures are expected in the south, heatwave conditions are likely across much of England and Wales especially, with parts of Scotland and Northern Ireland also likely to see some unseasonably high temperatures.  

“An active tropical cyclone season in the North Atlantic has helped to amplify the pattern across the North Atlantic, pushing the jet stream well to the north of the UK, allowing some very warm air to be drawn north. It’s a marked contrast to the much of meteorological summer, when the UK was on the northern side of the jet stream with cooler air and more unsettled weather.” 

The exception to the largely very warm conditions this week is the far north and west of Scotland, which will see some periods of showery rain at times, in addition to some North Sea coasts which may see some low cloud. There’s also a chance of some very isolated thundery showers crossing areas to the west from Tuesday, though this is unlikely to be very widespread. 

In addition to high daytime temperatures, which could see official heatwaves be observed from as early as Tuesday in some spots, it will remain uncomfortably warm overnight, especially in the south, with a chance of tropical nights, which is when overnight temperatures remain in excess of 20°C.  

The highest overnight minimum temperature for September on record is 21.7°C, and this record could be threatened on Wednesday and Thursday nights in particular.  

Heat Health Alert

The UK Health Security Agency, which provides alerts for the health and social care sector in England, has issued an Amber Heat Health Alert which highlights increased risks to those more vulnerable to heat.  

The Met Office has not issued an Extreme Heat Warning, which covers the UK and aligns with the wider national severe weather warning service and looks at more widespread potential impacts for the public.  

Help to protect the vulnerable people that you know including older people, those with underlying conditions and those who live alone; they may need support to keep cool and hydrated. For more advice click here.  

Dr Justine Shotton, Senior Vice President or the British Veterinary Association, said:

“We may be past the peak summer months but it’s important to remember that this September sun and heat is also dangerous for animals. Pets can be extremely susceptible to heat-related illnesses such as heatstroke, and can also suffer sunburn, heart conditions and breathing difficulties, many of which can sadly be fatal. Make sure all pets have access to fresh drinking water, good ventilation and shade from direct sunlight at all times.”

Thundery breakdown on the way

While the heat will probably peak on Wednesday and Thursday, at least in terms of spatial extent, temperatures and humidity will remain high for many in the south into the weekend, and there’s an increasing chance of some intense thundery downpours, most likely in the west.  

Met Office Deputy Chief Meteorologist Steven Keates said:

“A cold front will begin to influence things from the northwest towards the weekend, though it’ll remain very warm or hot in the south.  

“There’s a chance the thunderstorm risk to western areas from Friday onwards may require a warning response, with some potentially impactful downpours, though exact details on the likely positioning of these downpours are still being determined.” 

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