Motorists are being urged to take care as further snowfall hits Dorset, with up to 20cm (8in) expected in parts.
Most places are predicted to see between 10cm (3.9in) to 15cm (5.9in), with more on higher ground.
The old Sherborne Road near Giant's Head had become impassable but the A37 in the west of the county and the A35 near Bridport had reopened.
The Met Office issued a weather warning for the whole county, including coastal areas, for "very heavy" snow.
Heavy snowfall at the weekend brought difficult driving conditions on many rural roads.
Gritters are continuing to treat major routes however minor routes are not being gritted and may be hazardous.
Farmers using snow ploughs fitted to their tractors are assisting the gritting vehicles.
Dorset Police said the Old Sherborne Road, near Cerne Abbas, was becoming foggy and icy. A lorry had also become stuck in nearby Revels Hill.
Both sides of the Upton Bypass were only passable in one lane throughout the afternoon, police said.
South West Trains is running revised services and passengers are advised to check the firm's website for the latest information.
Meanwhile a concert by the Bournemouth Symphony Orchestra due to be held at Sherborne Abbey on Monday evening was cancelled.