Advanced weather modelling maps suggest that Brits could be basking in 30C heat before the end of this month, with up to 20 counties in England expected to see temperatures of 27C or above over five consecutive days.
According to the GFS weather model, maximum possible temperatures could rise to 25C and beyond starting on May 24, when highs of 27C are forecast for the south-east of England. Yorkshire could see 25C, while parts of Wales and Scotland may reach 23C, with Northern Ireland slightly cooler.
On May 25, the maps again show 27C highs in the south-east, with London expected to get the best of the temperatures. East Anglia could see 25C at around 6pm. Temperatures are then expected to cool slightly on May 26 and 27, with highs of 25C and 26C in the south-east and 20-22C across the rest of England and Wales.
However, May 28 could be an absolute scorcher, with maximum temperature maps showing possible highs of 30C just to the west of London. Elsewhere in the south-east, temperatures could reach 28C and 29C, with 27C highs extending as far north as Yorkshire. Scotland may see low-20s, while Wales could reach 25C, but Northern Ireland is not expected to hit 20C.
For an official heatwave, the Met Office requires temperatures to reach the heatwave threshold for three consecutive days. The threshold varies from 25C to 28C across the UK, with 28C in the south-east and 25C further north. Even if 30C is reached on one day, an official heatwave may not be declared.
The Met Office's forecast for May 18 to 27 states: "Temperatures near-normal to begin, but tending to recover as the period progresses, perhaps becoming rather warm by the end of the period, especially in the south."
