TfL Ref: FOI-0719-1718

Thank you for your email received by us on 21 June 2017 asking for information about temperatures on London Underground.

Your request has been considered in accordance with the requirements of the Freedom of Information Act and our Information Access Policy. I can confirm we hold the information you require. You asked for:

The highest temperature recorded on each tube line in 2017, 2016, 2015, 2014, 2013. Please record the line, the temperature, the station, date and time in the following format.

Bakerloo line

2013: 30 degrees, Oxford Circus, 31.08.13, 6pm

2014: 32 degrees, Waterloo, 16.09.14, 4pm

2015: 31 degrees, Oxford Circus, 13.09.15, 9am

Jubilee line

2013: 30 degrees, Oxford Circus, 31.08.13, 6pm

2014: 32 degrees, Waterloo, 16.09.14, 4pm

2015: 31 degrees, Oxford Circus, 13.09.15, 9am

London Underground records temperatures across the Underground in order to inform our cooling initiatives.

We note that your request was for maximum instantaneous values of air temperature recorded during operational periods for each line. Typically the maximum readings occur during evening peak periods and on the warmest day of each year. They can also be influenced by prolonged train dwells, maintenance activities and station closures.  Due to the influence of external temperatures and other operational factors, the instantaneous maximums do not give a good representation of the typical summer conditions on the tube network. Therefore we have also attached a document giving the average evening peak temperature data for each line over each year; which may fit your requirements better than instantaneous values.

Please find the information you requested in the table below:

Similar data for 2017 is not yet available.

We are investing millions of pounds as part of a long-term programme to ensure we can deliver more services and continue introducing new trains – to meet growing customer numbers whilst providing more comfortable journeys. We have implemented energy efficient solutions on new trains which saves energy and reduces the heat generated. We have also removed heat from our station and tunnel environment by installing new ventilation or cooling solutions.

For example, on the Victoria line we have doubled the capacity of thirteen ventilation shafts which provide more air flow, as well as introduced regenerative braking (energy that would normally be lost as heat is instead harnessed which then allows it to power the rails) on the new trains. We have also installed air cooling units and mechanical chillers at some key busy stations, such as Oxford Circus and have been using groundwater underneath Victoria Tube station to provide cooling to the platforms. We are similarly using water from the aquifer underneath Green Park to provide cooling for that Tube station. In addition we have upgraded existing ventilation fans and installed new fans at a number of stations across the network.

As part of this work to make customer journeys more comfortable, we are also working to reduce temperatures inside carriages. New, air-conditioned trains are now in operation on the Circle, District, Hammersmith & City and Metropolitan lines. We will be introducing 250 new Tube trains with air-cooled carriages on the Piccadilly, Bakerloo, Central and Waterloo & City lines, with the first new trains serving the Piccadilly line from 2023.

If this is not the information you are looking for, or if you are unable to access it for some reason, please feel free to contact me.

Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.

Yours sincerely,

Melissa Nichols

FOI Case Officer

FOI Case management Team

General Counsel

Transport for London