The Met Office has issued an amber warning of snow for parts of Scotland as snow gates remain closed in Aberdeenshire.
The weather centre has warned of outbreaks of rain and sleet turning to snow on lower ground with more than 10cm expected in higher parts of Dumfries, Galloway, Lothian and the Borders.
The Met Office chief forecaster said: "Please be prepared for some difficult driving conditions and the risk of disruption to travel, and take appropriate precautions before undertaking journeys."
The B974 between Fettercairn and Banchory is closed due to heavy snow and Police Scotland has issued warnings about black ice on roads in the north Highlands.
The Met Office has also issued yellow ice warnings for the whole of mainland Scotland.
The A835 Altguish near Inverness is also affected by lying snow but is currently open.
Temperatures could to plummet late on Wednesday evening.
STV weather presenter Jo Farrow said: "Low pressure coming in from the Atlantic today will come up against the cold air over Scotland this evening.
"This will result in snow across southern Scotland, with the Met Office issuing an amber warning for heavy snow for parts of Midlothian, East Lothian, Scottish Borders .
"Higher ground could see over 10cm, with low levels seeing a few cms too. It will be icy and driving conditions will be tricky, through into the start of Thursday morning.
"There is also an amber warning for snow for Sheltand tonight. This is from a different frontal system which is stuck over Sheltand today, bringing wet weather which could turn to heavy snow later.
"After this snow episode, there will be snow showers for the north and west but lots of sunshine and the cold weather will last right through the weekend."
Public health chiefs have warned the elderly to keep their homes warm and have the flu jab.
A widespread frost is expected across the country on Wednesday morning with temperatures reaching as low as minus 5C in parts of Scotland overnight, according to MeteoGroup.
Official figures showed winter deaths in the UK jumped by 151% last year.
Charity Independent Age is offering free advice to elderly people and their families to beat the chill.
Lucy Harmer, director of services at Independent Age, said: "Winter can be a testing time for many elderly people if they don't have enough social, financial or emotional support in place. We would urge older people, their families and carers to take extra care during the cold snap.
"The Government, councils and individuals all need to take more responsibility for ensuring older people are getting the support they need in winter."