Ice poses a real risk to commuters today as some overnight rain has frozen on surfaces such as roads, pavements and tracks.
However, many places will remain dry and bright, although outbreaks of rain are likely throughout the day.
Northern Ireland and northern counties of northern England are going to have the best of the sunshine today.
Meanwhile, the rest of England and Wales will face downpours, some of which will be quite heavy and blustery at times.
What’s more, strong winds across South Wales and south west England will intensify the impact of showers in those regions.
Meteorologist Sarah Keith-Lucas urged BBC Breakfast viewers to be careful when travelling because of the risk of ice.
She said: “It’s mixed fortunes during the course of the day, we’ve got a chilly start across the northern half of the country.
“And we’ve got a risk of some ice stretches across parts of Scotland on any untreated surfaces.”
Today, the temperature range has expanded, as the heat value in the north will be relatively low, with most places struggling to top five Celsius.
However, further south temperatures could reach a pleasant 14 Celsius, which is quite mild for this time of year.
This evening most sections of the UK will be consumed by patches of mist and fog, and there is going to be frost in places too.
Then, on Tuesday temperatures take a huge dip following the overnight movement of cold air from the north to the south.
The heat value could fall to a low as minus two in several parts of the UK, including Newcastle and Hull.
With conditions to worsen as the week goes on, bookmaker Coral has cut odds on the chances of snowfall this Christmas.
The bookies make it 1-3 from 1-2 for the white stuff to fall anywhere in the UK, following a surge in bets over the weekend.
Coral have put bets on which major UK city will see snow, with Aberdeen at 5-2, Manchester backed at 4-1 and London on 5-1.
“The probability of there being a white Christmas this year is increasing all the time according to the betting,” Coral’s John Hill reported.
“Now we are in December, we are being knocked over with bets on the white stuff falling on the big day.”
The firm is also offering evens on this winter to be the coldest on record at 1-2, as well as the coldest December in UK history at 10-11.
BBC Breakfast airs weekdays on BBC One at 6am.