The blast of hot air from Africa triggering the UK’s early heatwave will drag in a plume of brown dust throughout Wednesday.
It will sweep in from 2,000 miles away and remain in the air rather than settle on cars and windows as pollution levels rocket.
The 500-mile-wide dust cloud will see potentially high levels of smog smother northern, south west and central England, London and parts of Wales.
The government’s Department for Environment Food and Rural Affairs (DEFRA) is warning the high air pollution could spark health complications.
“Wednesday will be Britain’s worst air pollution episode for a year – since the Beast from the East, DEFRA forecasts show,” said Simon Birkett, director of campaign group Clean Air in London.
“It’s a perfect storm of three factors – Saharan dust, pollution from the continent’s power stations, factories and farming fertilisers, and light winds meaning homegrown traffic pollution doesn’t disperse.
“Studies show hundreds of people will die early this week as a result.”
DEFRA’s pollution forecast for tomorrow reads: “Moderate to High levels of air pollution are forecast to persist during Wednesday.
“There is a risk of localised Very High levels developing in urban centres of northern England.
“Air pollution levels are expected to return to Low from Thursday as winds increase from the west.”
The warm air drawn in from Africa will also see temperatures rocket to near 20C for the third day running tomorrow.
The mini heatwave has already seen record temperatures set, with the Met Office confirming Kew Gardens in London set a new hottest ever winter record with 21.2C.
Tomorrow could see that record beaten yet again, although Daily Star Online reported earlier how a washout will bring the scorcher to an abrupt halt halt this weekend.