Shortly after 11am, six lines were reporting delays because of the snow or “due to non-availability of staff.”
Bus services in the capital are currently all running.
Transport for London said its staff had worked “throughout the night” to de-ice roads and ensure Tube services could operate.
Leon Daniels, Managing Director of Surface Transport, said: “Around 2,000 tonnes of grit has been spread by TfL and boroughs and all main roads and the vast majority of local roads are open and traffic running smoothly.”
Daniels said staff were “working hard to keep planned services running on all Tube, DLR and London Overground lines and to keep London moving.”
“London is open for business today, but clearly people should take care on the roads and allow plenty of time for their journeys.”
Network rail services were also affected. Southeastern warned passengers that “with several inches of snow in some places there will be disruption and cancelled services.”
Southern also confirmed the snow had disrupted services and warned “trains are subject to delay and cancellation, with journey times extended by up to 30 minutes.”
There is also a reduced service running on the Heathrow Connect.
Heathrow airport said it would run a reduced service with 30% of flights cancelled. In a statement the airport said “without reductions to the flight schedule there would be significant disruption to flights and passengers at Heathrow.”
On Twitter a spokesman for Stansted said the airport was open but that “flights may be subject to delay” and advised passengers check with airlines before travelling and allow additional time to get to the airport.
Gatwick airport said it was “open for business & operating a full schedule” but also advised checking with airlines for any changes to schedules.
London City Airport said it expected to open “as normal at 12.30” and was working to clear the runway after the night’s snowfall.
UPDATE 17.50: By early evening services on most Tube lines had improved with delays largely resolved.
