Heavy snow brought chaos to South Somerset, Devon and Dorset, with dozens of schools closed, many trees brought down across roads and vehicles abandoned.

Two major routes through Devon were closed and more than 50 cars were abandoned. The A30 was the worst affected on Dartmoor near Okehampton, with 50 cars and 15 lorries stuck at various points throughout the night. The same area was hit last month when severe snow storms hit much of the south.

In Yeovil and towns and villages west towards Crewkerne and Chard motorists woke to find up to four inches of wet snow, turning to slush, which brought huge traffic congestion.

A jacknifed lorry closed the A37/A30 at Henford Hill, Yeovil, and in another incident, believed to be snow-related, a car driver was hurt in a collision with a lorry on the A358 near Taunton at around 2.50am.

Many people left their cars at home and trudged into work, a precarious business on pavements made treacherous by slush.

In Dorset the weight of the snow brought 50 trees down across major roads, but all roads were reported to be clear again by lunchtime. Major routes including the Yeovil to Dorchester road and the Ridgeway at Weymouth, as well as roads around Bere Regis, Wareham and Blandford were impassable and police warned drivers not to drive unless their journey was essential.

Dorset County Council had snowploughs and gritters out in force.

More than 50 schools in Dorset closed, while in Somerset Ashlands, Misterton and Hinton St George first schools, all near Crewkerne, closed, along with Tatworth primary school, near Chard. Wadham community school also closed and some others opened late.

In Dorset waste collections were disrupted and four day care centres were unable to open and mobile library services disrupted.

Devon & Somerset Fire & Rescue service was called to a power line which came down onto a house in Merriott, near Crewkerne, but it was not clear whether the weather was involved.

Bright sunshine cleared much of the snow by lunchtime but police and highways chiefs warned that with temperatures expected to drop again last night frozen slush could be another hazard overnight.

Dorset Fire & Rescue Service will today launch an extension to its co-responder scheme which can be especially valuable in severe weather conditions. It enables the fire service to administer basic life-saving treatment to patients if required prior to the arrival of an ambulance crew.

Trained staff may also be informed of an incident in their locality via a pager system on a round-the-clock rota basis and they act as a first response while an ambulance is on its way. The system is already in use in Lyme Regis and a six-month pilot scheme will be launched in Beaminster, which if successful, will become permanent. The system was launched after a request from ambulance services.

Other parts of Somerset – especially around Taunton – and West Dorset also saw some sizeable flurries overnight, making for difficult driving conditions.

The Highways Agency said: "Delays are likely to be severe and drivers are strongly encouraged to avoid the area or postpone their journey if they can."

A spokesman said agency gritters had been running a "full winter service" in the region overnight to try to keep roads open.

Nikki Berry, a forecaster with MeteoGroup, the weather division of the Press Association, said forecasters had not been expecting as much snow.

"The worst hit was Devon and Somerset, and it is possible we had up to 8cm in some parts.

"That was more than we expected. Some drivers had to wait for around an hour while the road was cleared."

Residents woke in Bournemouth and Poole to find snow settled on the beaches. Schools were open in the seaside towns.