Snowfalls across the UK have disrupted air travel and brought warnings for drivers in parts of Scotland.
There have been dozens of flights cancelled into and out of Glasgow, Edinburgh and Aberdeen, affecting more than 16,000 passengers.
The Met Office said heavy snow was expected in the Northern Isles, Highlands, east coast and the Borders.
All trunk roads have been open but there were road condition warnings in the north, north east and south west.
Heathrow Airport closed its runways to clear snow, while Gatwick reopened after closing this morning. BA has cancelled all short-haul flights.
Planes diverted to Glasgow have come from Dubai, Tel Aviv, Los Angeles and Chicago.
One passenger stuck at Glasgow Airport told BBC Scotland: "We're trying to get to Toulouse in France but all we can do is wait, we're trying to speak to the ticket people here."
Another said he was attempting to fly to Venezuela but now faced several days delay until he could get another connecting flight.
Aberdeen Airport has been experiencing delays and travellers were advised to check with their airlines.
Train services have also been disrupted between Aberdeen and Inverness and Edinburgh and Perth.
Northern Constabulary warned drivers to exercise extra caution and consider postponing journeys until weather conditions improve.
The force said most roads were affected by snow and ice to some degree, in particular in the Western Isles, Orkney and Shetland.
A spokesman for Grampian Police said drivers should decide whether their journey could be delayed until the weather improves.
He added: "Whilst a number of routes have been treated overnight we would urge anyone who does decide to travel to exercise caution."
In Dumfries and Galloway, police said drivers should avoid travelling if possible and snow has also been causing problems in Ayrshire.
Meanwhile, the Scottish government's resilience committee has continued to meet.
First Minister Alex Salmond told BBC Scotland the distribution of heating oil was a key concern.
He said: "We've been in a position where in the north and north east of Scotland we've been running very low.
"Fortunately we've got two tankers coming in of kerosene, both on Sunday and Monday into Aberdeen and Inverness, which is going to help the stock situation.
"Then it's going to become a question of logistics getting the stocks out to the people who need it, particularly vulnerable people, in time for Christmas."
Hundreds of flights in Europe have also been cancelled after heavy snow closed airports outside the UK.
Scott Allison, from Glasgow, has spent two days at Schiphol in Amsterdam, trying to get a flight home.
He told the BBC: "It's not only the UK that can't cope with the snow. There are literally thousands of UK residents who have now been stuck at various airports in mainland Europe for two days now.
"I was delayed one night at Stockholm and then a second night last night at Amsterdam. When will I get home? I have no idea yet and the customer service desk here at Schiphol is imploding."
Coastguard Rescue teams have been helping the NHS in the Western Isles, Northern Isles and west coast of Scotland.
Scottish Premier League games at Aberdeen, Hamilton, Rangers and St Johnstone were called off.
However, snow sports centres have taken advantage of the conditions. Glenshee and Cairngorm Mountain have opened to skiers and snowboarders and the Nevis Range opened on Saturday.