Fifth UK heatwave triggers health alerts as drought deepens across England and Wales

Yellow heat health alerts took effect at 9am on Saturday across all of England except the North East and North West, running until 9pm on Tuesday. The UK Health Security Agency warned that the hot weather is likely to affect the wellbeing of the population, particularly those who are vulnerable or have health conditions. The Met Office forecasts temperatures climbing through the weekend, reaching a high of 36C in parts of East Anglia and south-east England by Thursday.

This marks the fifth heatwave of the summer. The two record-breaking spells in May and June led to more than 2,800 excess deaths. Two further heatwaves in July caused river levels to plummet and sparked wildfires across the country. The highest temperature recorded this year stands at 38C at Lingwood in Norfolk on June 28. There have been 33 days so far when temperatures exceeded 30C somewhere in the UK, close to the record of 34 days set in 1995.

The alerts follow the driest July for England and Wales since records began in 1836. Nineteen counties across England recorded effectively no rainfall — 1mm or less — across the entire month. Half of England and the whole of Wales are now in drought, with 26 million customers subject to hosepipe bans. On Friday, the Environment Agency said several more areas could move towards or into drought next week after England received less than 10mm of rainfall for the seventh consecutive week.

Reservoir storage in England has dropped to 69 per cent, down from 72 per cent a week ago and nearly 12 percentage points below the long-term average for the time of year. Storage stood at 85 per cent at the end of June, the average for that point, but has fallen steadily since. Five reservoirs are now classed as having exceptionally low levels: Blagdon in Somerset at 54 per cent full, Clywedog in Powys at 62 per cent, the Dove group in Derbyshire at 74 per cent, Hanningfield in Essex at 60 per cent, and Wimbleball in Somerset at 50 per cent.

Forecasters describe a north-south split this weekend. Scotland and Northern Ireland will see spells of heavy rain, while England and Wales remain largely dry, sunny and increasingly warm. Temperatures could reach 30C on Saturday before climbing into the low 30s in southern and south-east England on Sunday. Highs of up to 30C are possible across parts of England and Wales on Tuesday, increasing to 32C to 34C on Wednesday, with the peak expected Thursday.

The Fire Severity Index indicates fires are likely to become exceptionally severe on Sunday for almost all of the east and south-east of England. The index, which uses Met Office data on rainfall, temperature and humidity, assesses the severity of fire if it starts — not the likelihood of ignition. Recent weeks have already seen large blazes at Dunwich Heath in Suffolk, Headon Warren on the Isle of Wight, Llanwonno in the Rhondda Valleys, and Cairngorms National Park in Scotland.

The National Trust has launched a petition calling on the government to make tackling climate change a national mission. The sequence of record-breaking heat, persistent rainfall deficit, and escalating health and environmental impacts illustrates a pattern that extends beyond a single summer's variability.