FOI request detail

Tube Temperature Measurements

Request ID: FOI-2633-1617
Date published: 21 June 2017

You asked

Please could you release any maps, datasets or reports on the temperature of different tube stations/lines/trains/etc that were produced in 2015, 2016 or 2017.

We answered

TfL Ref:2633-1617


Thank you for your web request received by Transport for London (TfL) on 27 March 2017 asking for information about any maps, datasets or reports on the temperature of different tube stations/lines/trains that were produced in 2015, 2016 or 2017. I apologise for the delay in replying.


Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.  I can confirm that we hold the information you require.


London Underground records temperatures across the Underground in order to inform our cooling initiatives. Based on this data please find attached a station platform temperature map from 2015 and a comparative map for 2013 – which are the latest figures available.


These maps are based on average temperatures monitored on station platforms between 1 August and 30 August from 4 to 7pm. The average ambient external temperature for 2013 was 22.2C with the corresponding ambient temperature for 2015 being 19.9C. Similar data for summer 2016 is not yet available. The map legend explains the colours illustrating the range of temperatures.


Heat on the Tube is generated mainly through the operation of electric trains – acceleration uses energy, some of which is released as heat during braking. Air is pushed by trains, piston-fashion, through station exits, ventilation fans and shafts. Heat is compounded by humidity and hence just improving air flow (even without a reduction in temperature) can have a positive impact on comfort levels for customers.


We are investing millions to cool temperatures 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 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 (which returns power to the rails while the train is braking) on the new trains. We have also installed air cooling units and mechanical chillers at key busy stations, including Oxford Circus and Euston, and have been using groundwater underneath Victoria Tube station to provide cooling on 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 also be introducing 250 new Tube trains with air-cooled carriages for the Piccadilly, Bakerloo, Central and Waterloo & City lines, with the first new trains serving the Piccadilly line from 2023.


Please also find attached a table showing monthly average evening peak hour platform temperatures by London Underground (LU) line for the period 2013 to 2016. The temperatures shown in the table were taken using a measuring device on each platform. There are many factors influencing temperatures from one year to the next and from month to month with outside temperature being one of the largest factors. Please note that SSL includes the District, Circle, Hammersmith & City and Metropolitan lines.


If this is not the information you are looking for, or if you are unable to access it for any reason, please do not hesitate 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



Sara Thomas

FOI Case Management Team

General Counsel

Transport for London


Back to top

Want to make a request?

We'll email you the response within 20 working days.

We'll publish the response online without disclosing any personal information.