UK Edition
Swathes of Britain will be warmer than central Spain this week, although new ice warnings were issued for early on Sunday in Scotland.
Northeast Wales, northeast England and even eastern Scotland could enjoy unseasonable temperatures as high as 15 degrees on Tuesday, while Madrid is expected to be three degrees cooler.
Meteorologist Helen Roberts said following freezing fog on Sunday morning and a “fine” day on Monday, general temperatures could rise to between nine and 12 degrees on Tuesday.
She added: “But a few favoured spots could see 14 or even 15 degrees, which is pretty good for this time of year.”
The warmest areas will be those in the north sheltered by high ground to their west.
A yellow "be aware" warning was issued for much of Scotland on Saturday, applying from 6pm until 10.30am on Sunday.
Lows of minus 7C (19.4F) were expected overnight and people were being warned to wrap up warm and take care on potentially slippy pavements and roads.
Forecaster Mark Wilson said: "It is going to be a very cold night, particularly across eastern areas.
"There will be some pretty dense freezing fog patches around as well, so if you are out for whatever reason it's best to wrap up and just be aware quite how cold it's going to be."
The Met Office's yellow warning states: "Icy patches will be a hazard on some untreated roads, pavements and cycle paths.
“Some injuries are possible from slips and falls on icy surfaces."
The warning also applies to parts of northern England, the Midlands, Yorkshire and Wales.
Towards the the end of the week a cold front from the north west will bring a return to December norms, with patches of overnight frost expected by Thursday or Friday.
Last weekend heavy snowfalls caused power cuts and disrupted travel by road, rail and air.
The deepest snow recorded was 30cm (12in) in Sennybridge, near Brecon, while High Wycombe saw 17cm.
Hundreds of schools across England and Wales were closed on Monday.
It is still too early to predict Christmas weather conditions with any certainty, but Bookmakers Ladbrokes are currently offering 4/1 odds on a snowflake landing on the tarmac at London’s Heathrow airport.
Those betting on snow in Glasgow or Edinburgh will only get 2/1.
The last time the UK experienced a White Christmas was in 2010 when snow or sleet fell at 19 per cent of weather stations across the country.