Southeastern and Southern rail services are expected to face some disruption tomorrow, according to the train operators.
Southern is introducing a special timetable which means there will be fewer services on some routes.
Southeastern is today experiencing some snow related problems but all lines are running.
Tomorrow the company is planning to cancel a number of early morning services to enable longer trains to run which reduces the possibility of failures.
An army of Southeastern staff volunteers are out at stations in Kent and Sussex to try to clear them of ice and snow.
The company says many workers have turned up at stations to carry out the work in an attempt to reduce the risk of injury for passengers.
Full details will be on the companies' websites later.
South West Trains and First Great Western will be operating as many services as possible but passengers are advised to check later tonight for any potential problems.
Chiltern Railways says significant snowfall is expected over the next 24 hours.
A spokesman said: "We will be running our regular timetable, but there is a risk we may experience delays and short notice cancellations. Please check before travelling."