Advanced weather modelling maps suggest that Britons could be enjoying temperatures as high as 30 degrees Celsius before the end of this month. Temperature anomaly maps indicate areas of deep red across the United Kingdom towards the end of May, particularly in England and Wales, where the mercury is expected to rise significantly above the seasonal average.
Five Days of Heat
The GFS weather model shows that maximum possible temperatures could reach 25C and beyond for five consecutive days, starting on May 24. On that day, data shows highs of 27C in the south-east of England. Yorkshire could see 25C, while parts of Wales and Scotland may experience 23C highs. Northern Ireland is expected to be slightly cooler.
On May 25, the maps again show 27C highs in the south-east, with London likely to get the best of the temperatures. East Anglia could see 25C highs around 6pm, according to the GFS model.
Temperatures are then expected to cool slightly on May 26 and May 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.
Potential 30C Peak
Maximum temperature maps for May 28 show possible highs of 30C just 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. Northern Ireland is not expected to hit 20C.
Counties Facing 27C or Above
In total, the GFS model suggests that as many as 20 counties could see temperatures of 27C or above across the five days, all in England. The full list includes: Yorkshire, Nottinghamshire, Lincolnshire, Leicestershire, Warwickshire, Staffordshire, Gloucestershire, Northamptonshire, Norfolk, Cambridgeshire, Oxfordshire, Bedfordshire, Buckinghamshire, Hertfordshire, Surrey, Berkshire, Sussex, Hampshire, Wiltshire, and Berkshire.
Will It Be an Official Heatwave?
An official heatwave is declared by the Met Office when temperatures reach or exceed the heatwave threshold for three consecutive days. The threshold varies across the UK, from 28C in the south-east to 25C further north. Even if temperatures reach 30C on one day, an official heatwave may not be declared. The Met Office says temperatures could turn "rather warm" towards the end of the month but has not yet confirmed a heatwave. Its 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."
