Britain is facing one of the coldest winters in 100 years with conditions causing "widespread, persistent and severe" problems this week, forecasters warned.

With up to four inches of snow in parts of the country yesterday, heavier deluges are predicted to hit many others later this week causing transport chaos on roads, trains and at airports.

MeteoGroup, the weather division of the Press Association, said up to 15cm of snow could end up lying over "wide areas" by Friday, with the south experiencing "significant or even major difficulties to infrastructures, particularly transport".

Temperatures fell as low as -10°C across southern England overnight, with no end in sight to the freezing weather.

Stephen Davenport, senior meteorologist at MeteoGroup, said: "This is stretching the limits of short to medium term forecasting but so entrenched is this cold weather pattern that it seems only a major upheaval in the atmosphere will bring a return to something milder.

"Should conditions continue in a similar vein, then by March we might just be looking back at one of the coldest winters of the last 100 years."

He added: "There are more immediate concerns in the shape of a very snowy spell this week.

"Heavy snow showers or more widespread snow will continue to move across northern and eastern areas of Britain, bringing further accumulations of several centimetres in places and causing notable disruptions to transportation.

"And the highly-populated south is likely to see snow that will at times be widespread, persistent and severe enough to bring significant or even major difficulties to infrastructures, particularly transport.

"By Friday or even sooner there will be several centimetres of snow lying over wide areas, to depths of five to 10, or even 15, centimetres. In a few ill-favoured areas the persistence and heaviness of the snow could bring accumulations well in excess of 20 centimetres."

The Met Office warned of heavy snow in the Scottish highlands, Wales, northern England and the Midlands.

Temperatures will barely top freezing during the day, with London set to be the warmest at 3C. Manchester could possibly touch 1C , Glasgow will hover around 0C and Cardiff 2C.

Commuters suffered more disruption as they returned to work after the Christmas break, with thousands of schoolchildren enjoying an extra day off due to the weather.

Yesterday the AA was experiencing its busiest ever day, with the organisation on schedule to attend more than 25,000 breakdowns over the 24 hours.

The AA also warned that the roads were likely to be even busier today when worsening weather conditions combined with the return to school in many areas. Grit stocks in England are holding up according to the Highways Agency, but Fife council in Scotland had to have several hundred tonnes of salt and grit delivered by the Scottish government after supplies ran low.

A Scottish government spokesman said Fife Council received 250 tonnes of salt and grit yesterday following a delivery of 50 tonnes the day before.

Highland Council also said it had used 30,000 tonnes of salt over the past three weeks - more than the total it used during 2006/7.

Yesterday, over-running rail engineering works caused 60-minute rush-hour delays to trains in and out of London's Liverpool Street station.

And on London Underground there were part-suspensions on the District and Hammersmith and City lines due to signal failures.

Even the fountains in Trafalgar Square iced over in the sub-zero temperatures.

Elsewhere, Merseyrail services were delayed by up to 30 minutes and rail passengers were hit by poor weather in Scotland which led to delays between Glasgow and Edinburgh.

Buses replaced trains between Ormskirk and Preston and between Boston and Skegness in Lincolnshire, while a signalling problem near Dagenham Dock in Essex led to delays on services to and from Fenchurch Street station in London.

Bookmaker Paddy Power cut the odds on this being the coldest January on record from 5/1 to 7/4.