The Victoria line is the hottest on the London Underground, with temperatures increasing by nearly a third over the past decade, according to data from Transport for London (TfL). In 2023,
the average platform temperature was 28.2°C, rising above 30°C between June and October.
The Central line (26.7°C) and Bakerloo line (26.0°C) follow as the next warmest. In contrast, the air-conditioned Circle, Hammersmith & City, District, and Metropolitan lines are the coolest, averaging 19.3°C.
TfL states it has implemented measures to reduce heat in stations and tunnels, including doubling the capacity of 13 ventilation shafts on the Victoria line. Despite these efforts, the average temperature on the Victoria line has risen from 21.9°C in 2013, marking a 29% increase over the decade.
Platform temperatures on the Tube are routinely monitored using data loggers. A decade ago, the Bakerloo, Central, Piccadilly, and Northern lines were the warmest, all with average temperatures below 26°C.
Additionally, a Freedom of Information request revealed 49 complaints last year about high temperatures on the Tube, while 15 people complained about it being too cold. TfL has installed air cooling units and mechanical chillers at busy stations, such as Oxford Circus, and utilizes groundwater beneath Victoria station to cool the platforms.
London Overground and Elizabeth line temperature figures were not included in the report. Photo by Victoria tube station, Victoria Line - ceramic tiles (2) by Mike Quinn, Wikimedia commons.