Parts of southern England are bracing themselves for a record-breaking two-week heatwave, with temperatures set to soar into uncharted territory. Merryfield in Somerset has already reached a sweltering 30.6C, part of an unprecedented 12 consecutive days above 30C – the longest such spell since 2006. While some cooler air is forecast from the north this weekend, several locations may still endure several more days of scorching heat.
This year's heatwave marks the third in as many months, with record-breaking temperatures already shattered in May and June by over two degrees. However, despite the UK's current streak mirroring 2006's record 16 days at or above 30C, the heat this year is proving more extreme, with six consecutive days exceeding 35C – a feat previously unseen. Moreover, it's the first time temperatures have consistently breached 35C in three consecutive months (May, June, and July).
The Met Office attributes the extreme heat to a combination of factors, including the UK's rapidly warming climate, which has seen average temperatures rise by 1.33C since 1961-1990. The agency highlights that the very hottest days have warmed even faster, by as much as 4.5C in Greater London. Meanwhile, this summer's unique weather setup – with a lingering jet stream to the north and high pressure dominating – has allowed a 'heat dome' to develop, intensifying solar heating and preventing cloud formation.
While Scotland and Northern Ireland have also been affected by heatwave conditions, the intensity and duration have been less pronounced than in southern England. The dry spell accompanying the heat has been particularly striking, with some areas like Wisley in Surrey recording no rainfall for 30 days. Most of Wales and Northern Ireland are experiencing rainfall deficits, although parts of western Scotland have seen above-average rainfall. Importantly, despite the dryness, drought conditions remain largely absent across the UK – a stark contrast to the widespread drought that accompanied the 1976 heatwave.
The Met Office's State of the UK Climate report paints a clear picture: heatwaves are becoming more frequent, longer-lasting, and intense. The report notes that the number of days above 30C has quadrupled in areas such as Greater London. Furthermore, heatwaves are increasingly occurring outside traditional summer months – evident in an autumnal heatwave last year and an unprecedented late-May heatwave this year that shattered both daytime and overnight temperature records.