Ice and freezing temperatures are to continue across the UK, as further snow falls - particularly in eastern parts of the country.
BBC Weather said snow flurries are expected for much of the UK throughout Sunday.
Up to 8cm (3in) is forecast for south-east and eastern England spreading to parts of north-eastern England later.
Travel disruption will continue and Heathrow Airport will be hit by a third day of cancellations and delays.
The airport has reduced Sunday's flight schedule by 20% because of forecast snow and low visibility.
Airport managers said the planned reduction - which amounts to 200-250 flights - should create enough space in the timetable to prevent any further cancellations.
Gatwick and Stansted airports are operating as normal, with teams on standby to clear snow if required.
In other developments:
The Met Office has issued a yellow "be aware" ice warning covering almost the whole of England, all of Wales and Northern Ireland, and the south-west corner of Scotland.
The warning says: "The public should be aware of the risk of localised difficult travel conditions due either to existing snow cover, or to icy surfaces."
There are also yellow snow warnings for eastern parts of England and Scotland, stretching across the Midlands into north Wales.
A fresh band of snow started falling in parts of south-east England on Sunday morning.
This is expected to move slowly north during the day to reach north-east England overnight and much of eastern Scotland by 06:00 GMT on Monday.
Forecasters said the snowfall would continue in much of eastern Scotland and north-east England on Monday, while there could also be flurries in southern England and Northern Ireland.
Cold weather is anticipated across the UK throughout Sunday, with temperatures at or about freezing in most areas and BBC Weather predicting a possible low of -8C in Dorchester, Dorset, on Sunday night.