London Braces for Record-Breaking 40°C Heatwave as Red Warning Issued

London is set to experience its hottest June days on record this week, with temperatures forecast to reach 40°C, prompting the Met Office to issue a rare red extreme heat warning for Wednesday and Thursday. The unprecedented heatwave has already led to school closures, transport disruptions, and urgent calls for residents to take precautions.

The Met Office has upgraded its initial amber warning to a red alert for parts of southern England, including London, as temperatures are expected to soar past the previous June record of 35.6°C set in 1976. Forecasters predict the mercury could hit 40°C on Wednesday, with similar highs continuing into Thursday before easing slightly on Friday. The heatwave will also bring tropical nights, where temperatures remain above 20°C, for four consecutive nights from Tuesday to Friday, making it difficult for residents to sleep.

In response to the extreme conditions, the Greater London Authority has published a "Cool Spaces" map detailing free air-conditioned venues such as The O2, Royal Opera House, and Imperial War Museum, as well as libraries, churches, and community centres where people can escape the heat. The map also highlights green spaces with shady tree canopies and public fountains for cooling off. Londoners are advised to stay hydrated, avoid strenuous activity between 11am and 3pm, and check on vulnerable neighbours, particularly the elderly and those with health conditions.

Transport services are expected to be severely impacted, with Eurostar cancelling some services and rail networks warning of potential delays due to heat-related infrastructure issues. The UK Health Security Agency has warned of a likely rise in deaths among vulnerable groups and significant strain on health and social care services. Fire chiefs have also urged caution around open water, as temperatures can remain dangerously cold despite the warm air.

Environmental groups have linked the heatwave to climate change, with Greenpeace UK’s head of climate, Mel Evans, calling the forecast "staggering" and emphasising the need to limit fossil fuel emissions. The Met Office has also stressed that reducing emissions is crucial to prevent the worst impacts of extreme weather. The heatwave is expected to ease by the weekend, but temperatures will remain above average into next week.