Parts of Scotland reached as low as nearly minus 18 Celsius (minus 0.4F) on Monday night, as the country faced Storm Darcy.
Bus and rail travel has been disrupted with an amber weather warning in place for much of the central belt and Transport Scotland reporting temperatures down to nearly minus 18 at Bannockburn in Stirling.
The Met Office forecasts that snow showers will continue during the day on Tuesday and into the evening across most of Scotland.
ScotRail reported delays due to staff struggling to get to work, while Transport Scotland urged care, following a number of accidents early on Tuesday.
The amber warning is in place until 9pm.
Speaking on Good Morning Scotland, Transport Scotland manager Stein Connolly said: “We had 146 gritters out last night.
“All the trunk roads are open, but there are some places where it’s just passable.
“There has been a couple of accidents – police are working to get these clear, but it’s maybe better to leave it until a safer point in the day (to travel).
“We did have temperatures down to nearly minus 18 last night at Bannockburn in Stirling, so it has been a challenge.
“It’s been minus seven, eight throughout the country last night.”
He added that people should leave plenty of travel time for their journeys, and ensure extra space between cars.
Mr Connolly said: “It takes up to 10 times longer to stop in the snow, so just make sure you’re leaving plenty of space.”
Parts of Orkney are dealing with power cuts, with all schools in the area closed, even to children of key workers, due to the weather.
Areas including Edinburgh and Glasgow have already faced a loss of electricity supplies amid the wintry weather.
Roads over higher routes are particularly expected to be affected by the snow, and some rural communities might be cut off.
STV weatherman Sean Batty reported that Braemar in Aberdeenshire has had record levels of snow.
In a tweet, he said: “Now recording about 70cm (27.6in) of snow lying in Braemar.
“Record we hold for Braemar is 68cm (26.8in) back in 2001, so looks like that’s gone.
“We’re not going to stop there either, still more to come tonight & tomorrow. Stay safe.”