Further disruption was on the cards for millions today after more than an inch of snow was forecast to fall countrywide.
The Met Office issued a severe weather warning for today and tomorrow as winds from Siberia were expected to send temperatures plunging below freezing last night and bring widespread snowfall today.
Workers in the South and the South-east were warned to brace themselves for travel chaos this morning as the treacherous conditions threatened to affect their journeys. Daytime temperatures were not expected to rise above 2C or 3C but bitter winds were expected to make it feel far colder.
Brian Golding, the Met Office head of forecasting, said: "After a mild Christmas and new year, we will notice a real change to some cold and wintry weather."
Stephen Davenport, a senior meteorologist at MeteoGroup, said: "Maximum temperatures will be between 0C and 3C over much of the UK but as high as 5C in places," he said. "The wind-chill will make it feel significantly colder, so there will certainly be some rather frigid conditions, along with showers of sleet or snow."
Snow flurries were predicted to begin in the South-east early this morning before spreading northwards across England and eastern Wales. South-east England and East Anglia could see as much as 5cm of snow. Snow was expected to settle briefly inland, although not in coastal areas where there is likely to be rain.
North-east England and eastern Scotland are set to see the coldest weather from this afternoon onwards and can expect 5cm on low-lying areas with up to 20cm on high ground.
However, this week's big freeze is expected to have faded by the weekend, with milder weather arriving from the west on Friday and Saturday.
In the past, even the lightest snow flurry has been enough to cause traffic chaos and driving could be hazardous on icy roads in the worst-hit areas. The Highways Agency has issued an urgent alert to motorists telling them to check conditions before setting out and, if possible, to postpone their journeys.
The agency has put its entire fleet of 500 gritters on alert.
A spokesman said: "The south-easterly wind will make it bitterly cold for anyone who is unfortunate enough to break down. Road-users are advised to be prepared with warm clothing and an emergency pack, which includes food and water, a torch and a shovel."
The AA predicted about 45,000 motorists could break down in the icy conditions. It expects there will be 70 per cent more call-outs than a normal day. Adam Ashmore, a patrolman, said: "Over Christmas , people often tend to use just the one car, so many second cars just get left sitting in freezing damp conditions."