London and large parts of southern England experienced a rare tropical night and provisional record daytime highs in May, prompting health alerts and infrastructure strains
The city of London and wide areas of southern England experienced an extraordinary spell of warmth that produced a true tropical night and multiple provisional daytime records. Observations showed temperatures failing to fall overnight at some monitoring stations, with Kenley Airfield remaining above 21.3C through the night, marking the second straight night in May where the highest daily minimum temperature was exceeded.
In the daytime, Kew Gardens recorded a provisional peak of 34.8C, a reading described by forecasters as exceptional for the month.
Forecasters warned that the heat was not finished. The Met Office and senior meteorologists highlighted the potential for further highs of around 35C, possibly reaching 36C across large parts of southern England and Wales, depending on how afternoon thunderstorm development unfolds.
Around 97 monitoring sites reached or passed the 30C mark during the surge, and a set of locations saw their May records surpassed, underlining the breadth of the event.
Where the records were set
Across the region a dozen sites topped their previous May maximums, with the Met Office naming specific readings that underscore how widespread the heat was.
Among those were Heathrow (reported at 34.4C), Northolt (34.2C), Teddington (34C) and a string of readings from Benson, Wisley, Reading University, Wellesbourne, Cippenham, Brize Norton, Charlwood, Houghton Hall and Santon Downham, many in the low-to-mid 33C range. Two sites, Marham and Woburn, matched their May highs. The month’s previous warmest night had itself been broken the night before when Kenley Airfield recorded a minimum of 19.4C, illustrating how both daytime peaks and overnight minimums were notable.
Health, services and immediate impacts
Officials moved quickly to respond to the health and infrastructure challenges that accompanied the heat. The UK Health Security Agency issued an amber alert for heat — the first of 2026 — warning of potential strain on health and social care services and remaining in force through the following Wednesday. Utilities also felt the pressure: South East Water apologised after roughly 500 properties experienced outages or low pressure and crews distributed bottled water in affected areas. Emergency services tackled fires and incidents connected to the dry conditions, including a substantial grass fire in Holyrood Park, Edinburgh.
Advice and precautions
Authorities and charities issued practical warnings for those at risk. The AA reminded drivers that vehicle interiors can soar — potentially above 60C when outside temperatures reach 27C — while Age UK urged older people to avoid the hottest hours between 11am and 3pm, to keep cool with regular cold baths or showers and to seek shade or air-conditioned spaces if possible. Forecasters stressed that sudden afternoon convection and thunderstorms could alter peak temperatures and posed an added hazard by producing localized downpours and lightning.
Climate context and longer-term concerns
Meteorologists and climate researchers pointed out that these extremes are occurring against a background of long-term warming. The Met Office highlighted how rapid swings from cool conditions to sudden heat have become more frequent, while studies cited by forecasters estimate that breaking such heat records is now roughly three times more likely in today’s climate than it would have been without increased greenhouse gas concentrations. Climate advisers and committees have been urging adaptation measures, including proposals to install air conditioning in care homes and hospitals within a decade and in schools within 25 years, to cope with rising summer extremes.
Looking ahead, forecasters advised that the situation remained fluid: a further day or two of very high temperatures was possible across the Midlands, the south-east and south-west of England, East Anglia and South Wales, but the precise peak would depend on whether afternoon storms develop and dissipate the heat locally. The recent sequence of record daytime and overnight readings underlines how both immediate precautions and longer-term planning are now part of the conversation when unusually early-season heat arrives.
