Temperatures plummeted as low as -10.7C (12.7F) at Aboyne in Aberdeenshire last night, beating the previous mark of -10.5C (13.1F) recorded on January 3 in Braemar.
In Edinburgh, temperatures were a chilly -3.6C in the early hours of Friday morning, while Glasgow felt lows of -2.2C at 2am today.
A yellow warning of ice and up to 3cm of snow along the east coast of England is in place until 10am while a yellow warning of hill snow in Wales is in place until 1pm.
The Met Office said it would be a frosty start for most places while people in eastern parts were warned of the possibility of icy patches.
Rain and snow was forecast over some western parts during the morning commute, although snow was mainly expected on high ground.
Meteorologist Alex Burkill said: “Winter’s here now properly. It feels like winter and the weather’s resembling it.
“I think in Wales, many places are likely to see some sleet or snow.”