London Underground temperatures near 40°C as heatwave overwhelms the capital

A heat dome over western Europe pushed the United Kingdom to its hottest June day on record, with outdoor highs of 36 °C in Gosport and 35 °C in London. Inside the London Underground, temperatures on the Central line reached 39.4 °C, while other lines recorded between 22 °C and 37 °C. Commuters described the conditions as “hellish,” reporting “sweating buckets” and seeking relief by standing near windows or avoiding the Tube altogether.

The extreme heat strained the aging network, which lacks air‑conditioning on most trains, and contributed to service delays and occasional suspensions. Transport for London warned of disruptions and urged passengers to consider alternative travel. The heatwave also spurred a surge in micromobility, with e‑bike providers reporting up to a 28 % rise in journeys on hot days, and prompted calls for accelerated rollout of air‑conditioned trains.

Employers faced pressure to protect staff, as UK law imposes a duty of care but no set temperature limit. Guidance urged flexible working hours, additional breaks, and provision of drinking water. Legal experts highlighted proposals for a maximum working temperature, citing Spain’s 27 °C limit.

Retailers and consumers turned to personal‑cooling solutions, from wearable devices like Sony’s Reon Pocket Pro Plus to practical tips borrowed from residents of hotter climates. Health officials warned of heat‑related illness, especially for vulnerable groups, as the Met Office issued red extreme‑heat alerts for the capital.