National Rail has urged people to “only travel if absolutely necessary”.
There is disruption and cancellations to some rail services because of the severe weather with Avanti West Coast, Northern and Transpennine warning passengers to check before travelling.
Network Rail said that while all lines across the North West would remain open, operators would run amended timetables to help manage the impact of extreme temperatures on the railways.
For safety reasons, trains will operate at reduced speeds, meaning journeys will take longer and there is a heightened risk of delays, cancellations and last-minute alterations.
There will be no rail replacement bus services during this period.
Merseyrail said because of the expected temperatures, Network Rail had put speed restrictions in place on the Headbolt Lane line, and the service would run every 30 minutes.