This information was relevant to Friday 18 January. Follow the links for more information on your route.
The Northern line has experienced a few faulty trains on the above ground sections. UPDATE: TfL claims a good service but we're seeing tweets about the Barnet branch – not many trains and the ones there are, are full.
The Circle and District lines have also been disrupted by a faulty train at South Kensington. UPDATE: The Circle line is now running anti-clockwise and the District has minor delays between Barking and Upminster.
UPDATE: Earlier disruption because of a signal failure at Baker Street is now cleared on the Metropolitan line – only for a signal failure at Great Portland Street to cause minor delays. This is also affecting the Hammersmith & City line.
TfL are also having problems caused by staff not being able to get into work.
East Coast are recommending people travel early and have lifted ticket restrictions for journeys from and to King's Cross.
On First Capital Connect, a train broke down at Blackfriars earlier and the knock-on effect is delays of 30-60 minutes. Trains out of King's Cross are running on time.
First Great Western are lifting ticket restrictions, too. Departures from Paddington look normal.
Greater Anglia are running trains at slower speed which will mean a few cancellations this evening. Departures from Liverpool Street are currently OK.
London Midland tickets can be used on Virgin Trains out of Euston, but there's currently no problem.
Southeastern UPDATE: there are cancellations and delays of up to an hour from London Bridge. There's a broken train at Bromley South. Tickets are being accepted on buses, DLR, tube and high speed services. You're advised to start going home now. We're also seeing tweets that say there's no service from St Pancras to Sevenoaks.
Southern UPDATE: trains are now running between Purley and Tattenham Corner. Departures from Victoria and London Bridge seem normal.
South West Trains are running a revised timetable, which will also be in operation over the weekend. Waterloo is currently looking fine.
Virgin Trains have also lifted ticket restrictions and are offering full refunds for anyone with tickets for 18 and 19 January if you decide not to travel.
Power supply problems have been plaguing the Overground all day. UPDATE: everything seems to be running at the moment, but keep an eye on it.
The K4 is terminating at the Bridge Road Roundabout in Chessington. All other routes running as normal.
Heathrow had to close its northern runway for de-icing this morning, and City Airport was also closed for an hour for the same reason. Check with your airline if you're due to fly today or over the weekend.
Emirates Cable Car
Currently running fine. Someone on Twitter (we forget who, sorry) pointed out that it'll be like being in a snow globe.