Network Rail has closed all its routes in Kent, and services to and from most big London stations have been suspended as Storm Eunice tore across southeast England, making travel treacherous.
Fallen trees blocked lines all lines in southeast London, rail chiefs said as they pleaded with people not to travel.
The storm wreaked havoc across the UK on Friday after the Met Office issued two red weather alerts - the most severe - for London and southern England.
Network Rail Kent and Sussex said it would reassess the risk after 3pm on a line-by-line basis but that it was no longer safe for its staff to work or trains to run.
“There are no trains running in Kent, many parts of Surrey, Hampshire and further west, and a limited service in Sussex and south London,” Network Rail said.
Follow live: Storm Eunice leaves 43,000 without power as winds and snow cause travel chaos
Wind speeds of up to 120mph were recorded as the storm battered the southeast, pulling up trees, damaging homes and causing power cuts to tens of thousands of homes.
The Southeastern rail company, which covers London, Kent and East Sussex, warned would-be passengers that trains en route to destinations would be moved to the nearest safe location and stop there.
Engineering teams started work to clear a large number of trees blocking lines across the network.
At Banbury, Oxfordshire, a building’s roof was lifted off and blown onto tracks.
At Hildenborough in Kent, passengers were stranded during the morning when a fallen tree became tangled in a train’s power-collection equipment. Workmen rushed to the site to untangle it.
“We have a critical wind speed of 90mph, above which we cannot run trains,” Network Rail in Kent and Sussex tweeted at lunchtime.
“Closing the railway down predictably like this means we can move trains into stations and warn people in good time, instead of reacting suddenly and potentially stranding people.”
More than 15 trees were reported to have fallen on rail lines between southern England and the London Waterloo terminus.
Earlier, rail chiefs had advised passengers not to travel unless they “absolutely have to”, warning journeys would take longer and be disrupted, and passengers may not be able to complete their journeys.
Speed restrictions would be in place all day, the company said.
Train operators across Britain urged passengers to avoid travelling, and all services across Wales were cancelled for the entire day.
