Temperatures are set to rise to the mid 30s in parts of southern England as high pressure brings more hot, dry weather, following months of low rainfall which have left the country facing the spectre of drought.
And Scotland is set to also experience its own run of warmer weather, with temperatures forecast to hit 26C in Edinburgh on Thursday and the same peak in Glasgow a day later.
With temperatures expected to peak in the high 20s in south-east Scotland, the Met Office Scotland said north of the Border could reach official heatwave criteria by Friday.
A level three heat health alert for southern and central England has already been issued starting from Tuesday and running until Saturday.
The conditions have left the countryside, as well as urban parks and gardens, extremely dry, raising the risk of more devastating wildfires, with rivers, groundwater and reservoirs at low levels.
Two water companies have already announced hosepipe bans and others have warned they may need to follow suit – and there does not appear to be any immediate let-up in the dry, hot weather for southern parts of the country.
Essex County Fire and Rescue Service is urging people not to light barbecues or bonfires, or let off fireworks or sky lanterns, after a large fire that damaged gardens, sheds and trees was started by a chiminea.
Area manager Neil Fenwick said: “The ground across Essex is extremely dry allowing fires to spread easily and quickly. This is true for gardens as well as fields and heathland.
“Please help us to help you. Please don’t have barbecues or bonfires. Please don’t use fireworks or set off sky lanterns.”
The Country Land and Business Association (CLA), which represents 28,000 farmers and landowners in England and Wales, has demanded retailers follow the lead of Marks and Spencer and ban the sale of disposable barbecues across the UK this summer.
The organisation’s president, Mark Tufnell said: “The CLA is demanding that retailers immediately ban the sale of disposable barbecues across the UK this summer in a move to curb fires spreading in the countryside, which cause great damage to rural communities and businesses and jeopardise the safety of all those in the surrounding areas.”
The calls come as the Met Office is forecasting another week of sweltering weather for some parts – although the UK is not expected to see the record-breaking temperatures of July’s heatwave, where thermometers topped 40C for the first time.
Met Office spokesperson Grahame Madge said: “We’re expecting the heat to build toward the end of the week, and expecting temperatures of 34C or 35C across parts of southern England.
“After that the heatwave will start to subside.”
Low rainfall in July has left river flows in eastern Scotland as well as central, southern and eastern England below normal – with many seeing “exceptionally” low levels of water flowing in them, the UK Centre for Ecology and Hydrology (UKCEH) said.
Lucy Barker, a hydrological analyst at UKCEH, said: “Groundwater levels and reservoir stocks are likely to continue to decline in these areas.”