Forecasters believe yester-day was the coldest March day in 27 years, as the mercury plummeted to -12C in parts of South Lanarkshire, while hundreds of drivers were left stranded after blizzards in Sussex.
Tailbacks of up to 15 miles were reported on the A23 between Crawley and Brighton, with some motorists stuck for up to eight hours or abandoning their cars.
Ice and snow made roads across much of the South East of England impassable, after around 10cm of snowfall.
Police said snow and ice had caused hazardous conditions and officers were trying to help gritting lorries through to treat roads.
Inspector James Biggs, from Sussex Police, said: "Many drivers have been rescued but I know many more have endured long hours stuck in their vehicles. "
Red Cross volunteers were also checking on the welfare of stranded motorists.
Meanwhile, more than 100 people were stuck for more than four hours on the A2 near Dover after a lorry jackknifed last night, Kent Police said.
This morning rail services into Glasgow were disrupted when doors on a train were discovered to be frozen shut.
It led to the 07:42 Milngavie to Queen Street being cancelled during the rush hour to the disbelief of commuters who had been stranded at Bearsden yesterday due to signalling failures at Carstairs and Lanark.
A ScotRail spokeswoman said the 07.59 train called at all stops but was three minutes late and apologised to passengers.
But office worker Fiona McMerriel, 51, who was also caught up in yesterday's disruptions, said: "You couldn't script it."
Elsewhere, Channel tunnel high-speed Eurostar services were affected, by snow in France. The firm, which travels to Paris and Brussels, suspended services, poten-tially for the day.
The cold weather is set to continue tomorrow but a Met Office spokesman said: "The best of the sunshine will again be around Glasgow."