How Hot Does It Get On London's Public Transport?

Rachel Holdsworth
By Rachel Holdsworth Last edited 36 months ago
How Hot Does It Get On London's Public Transport?

It's been the hottest day of the year. What better way to spend it than with a digital thermometer that tells temperature and humidity, travelling on various methods of public transport? Yeah, we can think of about a thousand better alternatives too, but this is what happens at Londonist...

Central Line

Oh, piss off.

The winner, in a game where everyone loses, is the Central Line. It's notorious for being the hottest tube line, but even we weren't expecting the temperature to nearly hit 36°C between Oxford Circus and Liverpool Street. Fans behind the seats tried their best but we suspect you'd get more effect by holding a farting kitten to your face. (Do not do this: transporting kittens in these temperatures is probably illegal.) On the other hand, there is a vague breeze through the carriage through the windows at each end, which at least makes the Central Line feel better than...

New Bus For London


The New Bus for London has many names. Boris Bus. New Routemaster. We'd like to offer one more: Mobile Sweatbox. (Actually, we have another one in mind, but it's unprintable even by Londonist's liberal rules on profanity.) With no windows that open and an air 'cooling' (not conditioning) system that was even less effective than the Central Line's, temperatures are equal to the worst tube lines — but, crucially, zero breeze. Who designed this piece of crap? Thomas Heatherwick, please stick to Olympic cauldrons.

Your deeply unhappy and sweaty author.



Not wanting to be too mean to the Boris Bus, we went upstairs on a normal double decker: the 185 between Forest Hill and Lewisham if you want specifics. Just as empty as the Boris Bus number 10 we caught between King's Cross and Oxford Circus, the temperature reached about the same — but with all windows open the experience was very different. Also note the humidity level: the lowest we encountered all day.

Northern Line

Snapped at Old Street.

Only 31.1°C? Why, this is positively Scandinavian. Despite being another deep tube line, the Northern's had improvements to its ventilation systems and these days converts more of its braking friction into energy rather than heat. We could genuinely tell the difference.

Docklands Light Railway


With open windows and trains ploughing through the open air, the DLR feels relatively balmy. In case you can't read that photo, the temperature is 31°C but felt cooler than...



54% humidity? Ew, that's sweaty. Even with open windows.

Overground / Hammersmith and City Line


We did catch one of the new(ish) air conditioned sub-surface line trains between Liverpool Street and Whitechapel, but sadly two stops was not enough for our thermometer to properly take a reading. We reckon Overground trains are about the same, so if you want to cool down in a heatwave we recommend heading for one of these. Yes, we do appreciate that 28°C isn't exactly 'cool'.

Last Updated 01 July 2015

John McGill

Should have waited until rush hour

Joanne Smith

I was in London last Summer and there was a heat wave that week. It was the week of July 14th -19th. I was riding the tube one morning and we had to stop because a lady had passed out from the heat and if I'm not mistaken it was on the Central Line.

Tom Maybey

My South West Trains train to work had no (or not very good) air conditioning and the windows were bolted shut. Agahgahaghagagggghh.


They changed my daily old bus to a new bus without window... I feel like sauna inside, not even in summer = =# now...I don't even want to think about it


having had to schlep into the West End for two theatre reviews on the hottest days of the year, I have perfected a 'cool route': DLR with all windows open to Bank, change in comparative comfort in Bank/Monument's air-cooled station, wait for a 'new' air-conditioned Circle/District line (about a one-in-three option and worth the extra 4 minutes) and arrive anywhere from Cannon Street to Victoria in undehydrated state!

Keith Molloy

Re: the ' new bus for London's ' air cooling system. The nickname that these buses got during the summer of 2014 was 'Boris's boilers! The first routes to get these buses were the 24, 11 , 9, 390 these were the earliest versions ( with fleet numbers up to about LT100) There are over 500 in service with the latest on route 73 running in to Victoria. I suspect that the air con on the later buses has been improved as this problem is no doubt causing TFL major embarrassment

Having worked in the passenger transport industry for nearly forty years every type of bus that I know of that has had sealed windows and air con has had to have opening windows retrofitted.

The best system that I have seen is to have opening windows with locks fitted so the driver can open them in an emergency with a special key should the temperatures get unbearable or the system fail , I believe London overground trains have a system such as this


For reference, what were the readings in the street, in both direct sunlight & shade?


Oh, for the days when you could simply open the windows!