Commuters are being told to expect cancellations and alterations on Greater Anglia, c2c and TfL Rail services from tomorrow night.
Sub-zero temperatures and large amounts of snow are forecast this week.
Greater Anglia is drawing up contingency plans for train services from Monday evening onwards.
Southend Victoria to London Street will run a reduced service from 6am to 10pm on Tuesday and Wednesday, with all services finishing by 10pm tomorrow.
In a Tweet, TfL Rail said: “Due to predicted snow and icy weather we may be running a reduced or altered service from late Monday evening onwards. If this is implemented we aim to advertise this from Monday so please check nationalrail.co.uk and monitor social media messages.”
TfL services are expected to stop at 11pm.
c2c says a normal timetable is planned on Monday until 9pm, after which some services will be altered or cancelled. It is also expecting further alterations and changes later in the week.
