Through Freedom of Information Requests and data obtained from London Datastore, office space rental firm Making Moves has predicted which lines will be the hottest.
The Victoria Line is expected to be the hottest underground service this summer with temperatures expected to reach 32C.
According to Making Moves, from 2021 to 2024 the Victoria Line consistently recorded the average hottest temperature, with an average of 28.1C for the entire of 2024.
In second place with a predicted maximum temperature this summer of 31.4C is the Central Line.
The predicted maximum temperature of tube lines this summer (Image: Making Moves) Making Moves said: “The Central Line has the second highest maximum predicted temperature for 2025, likely to peak at 31.4C in August.
“The Central Line is one of London’s oldest and deepest lines, therefore it’s no surprise that limited ventilation contributes to making this line being one of the hottest.”
The Bakerloo Line is expected to have the third hottest temperature with 30.1C while the Northern Line follows closely behind with an estimated maximum of 29.9C.
The Piccadilly, Jubilee and Waterloo and City Lines had the coolest predicted maximum temperatures with 27.7C, 26.2C and 25.1C respectively.
Data for The Circle, District, Hammersmith and City, DLR, Elizabeth, Metropolitan, London Trams, IFS Cloud Cable Car and all London Overground Lines was not included in Making Moves’ research, as individual temperature records for these lines were not available at the time of writing.
Making Moves also sent a Freedom of Information request to Transport for London, which revealed the number of heat-related complaints from March 2022 to April this year.
The Victoria Line had by far the most with 78 complaints, peaking with 30 in 2023 alone.
The Central Line followed with 19 complaints, peaking with 9 in 2024.
The Northern Line registered 15 complaints whilst the Jubilee Line had 10.
The Piccadilly Line has had eight complaints since March 2022 and The Bakerloo Line had the lowest from the available data with only four – three of which came in 2024.
Transport for London offers the following advice on how to look after yourself when travelling in hot weather:
- Stay hydrated and always carry water
- Do not board a train if you feel unwell
- If you feel unwell while travelling on a train, get off at the next stop and contact a member of staff
- Where possible, consider retiming journeys to less busy times
