Snow and freezing conditions in the North East and Scotland were causing widespread travel disruption today, with icy temperatures everywhere else creating similar problems for commuters.
There is no sign of a let-up in the wintry weather, with bitter winds increasing and more parts of the UK including London facing snow in the coming days.
So far Scotland and the North East have been worst hit by snow, with more than a foot or more in parts, and police have advised people to stay indoors for all but essential travel.
Forecasters warned the rest of the country is likely to be blanketed this week as the weather front moves west.
The severe conditions could also last well into next week, with rain, sleet and snow.
A spokesman said: "Conditions are horrendous and we would urge caution."
All schools in Dundee, West Lothian and Shetland were closed this morning.
Across York and North Yorkshire, around 50 schools were forced to close this morning.
Several schools in East Yorkshire also closed for the day.
Driving was described as hazardous across many parts of Yorkshire as more snow began to fall.