Big chill set to last several days as Britain is reduced to a go-slow The Tan Hill Inn in Yorkshire, the highest pub in the British Isles. Snowfall of up to 15cm was expected in parts of Britain after temperatures dipped to -10C. Photograph: Gary Calton For The Observer/Gary Calton Dozens of flights across Britain were cancelled on Saturday night while motorists were warned they faced a "dangerous cocktail of driving conditions" as the big chill took hold of the country. Forecasters added that they expected the freezing weather to last for several days. Parts of the UK were placed on amber alert last night, the Met Office's second-highest severe weather warning, and most parts of the country are expected to wake up today to a blanket of snow, with up to 15cm forecast in some places. London's Heathrow airport is also expected to be badly affected and a third of today's flights there were grounded on Saturday nightin the fear that snow and freezing fog could disrupt operations. Heathrow's chief operating officer, Normand Boivin, said the decision to introduce a revised flight schedule before snow had actually fallen had been taken in an effort to minimise disruption. British Airways said it would allow passengers booked on Sunday flights to rebook for journeys between Monday and Thursday. Southern Railways also reported it was reducing services on some of its routes on Sunday. The cold snap has already seen daytime temperatures fall four or five degrees lower than average for February. A temperature of -10.6C was recorded in Chesham, Buckinghamshire, at 2am on Saturday, and of -10.3C in Benson, Oxfordshire, making it the coldest night of the year so far. "We have got a band of rain, sleet and snow pushing in from western parts," said Met Office forecaster Michael Lawrence. This is running over colder air and that's going to give some fairly significant snowfall, mainly in eastern and central parts of Britain and - to some extent - large parts of the UK. While the worst snowfall will be restricted to Cumbria, Lincolnshire, East Anglia and the Midlands, many other regions will still get significant falls of between 5cm and 10cm. Wales and the south-west, along with parts of western Scotland, will mostly see rain, however, as will Northern Ireland. The freeze, which is likely to continue this week, is also expected to cause treacherous conditions on the roads. "It looks like we're going to get a dangerous cocktail of driving conditions this weekend, with heavy snow and sub-zero temperatures making the roads extremely treacherous," said Kevin Andrews of the RAC. The motoring organisation said it was attending 70% more breakdowns than normal. The AA added it had been called out to deal with more than 4,300 vehicles on Saturdaymorning and the figure was expected to reach 16,000 by the end of the day, almost double the 8,500 callout for a typical Saturday. Motorists were also advised to take shovels, warm clothes and fully charged phones on their journeys. However, the Local Government Association (LGA) pledged that an army of council staff and volunteers would be ready to brave the conditions to make sure vulnerable people were cared for. It said: "Thousands of new grit bins have been placed in estates and side streets, residents have been given their own bags of salt along with salt spreaders in some neighbourhoods, and arrangements have been made with parish councils, community groups, snow wardens and farmers to grit hard-to-reach areas. Information about school closures and bin collections is also being updated regularly online. British Gas added that its fleet of all-weather 4x4s was on standby to get engineers out to customers. The company said it had received more than 200,000 calls in the last five days, compared with 120,000 to 140,000 during a normal winter week, and was expecting a further 50,000 this weekend, compared with 20,000 normally in the winter. The Department for Transport has said it is better prepared than ever for severe winter weather. Salt stocks across Britain stand at more than 2.4m tonnes - a million more than last year. However, the charity Age UK warned that it was a dangerous time for older people. Besides the risk of flu, low temperatures raise blood pressure, putting people at greater risk of heart attacks and strokes. Among yesterday's sporting fixtures that were postponed because of the weather were Portsmouth's game against Hull and Doncaster's match against Reading. In League One, Bournemouth against Exeter, Sheffield United's clash at Colchester, Oldham versus Leyton Orient and Charlton against Rochdale were also postponed as were Preston's game against Brentford, Stevenage's trip to Notts County, and the Bury versus Hartlepool match. Walsall's trip to Scunthorpe also fell foul of the weather. In Scotland, Falkirk's Scottish Cup match at Ayr was called off while, of the country's league programme, only the Third Division games at East Stirling, Montrose and Queens Park went ahead.