Travel warnings have been issued as freezing temperatures bring snow and ice to large areas of Scotland, England and Northern Ireland.
Disruption to road, bus and rail networks is possible, according to the Met Office, while there is a likelihood of people suffering injuries as they slip and fall in one of the first icy periods of the winter.
Motoring organisation the RAC urged drivers to “ensure they’re winter ready as some get their first real taste of snow and ice”.
The cold air is a result of a blast of cold air from Scandinavia, causing a cold snap for many in the north.
With temperatures dipping to the low single figures, – and below freezing overnight – several yellow weather warnings are in place.
One covers areas in north-east England, the East Midlands, the east of England, Yorkshire and Humber and parts of Scotland – and will be active from 5pm on Thursday until 11am on Friday.
Another, affecting Cornwall, Devon, Dorset and Somerset, will be in place until 4pm on Thursday.
An earlier warning remains in place until 11am on Thursday for eastern Scotland and north-east England down to North Yorkshire, where snow caused closures on the A169.
The Met Office said the three lowest temperatures recorded at its observation sites overnight were all in Cumbria on Wednesday, with a low of -7.2C in Bridgefoot, -6.5C in Shap and -6.1C in Keswick.
The BBC reported that parts of the UK had their coldest November night since 2010, and that it was -8C at Aonach Mor in the Scottish Highlands.
The UK Health Security Agency (UKHSA) has issued warnings of its own, with yellow and amber cold-health alerts for northern regions of England until December 5.
Yellow snow alert in force as Arctic blast sends temperatures plummeting (The Independent)
How cold does it have to be to snow in the UK? (Oxford Mail)
Temperatures across the UK in the coming days
(forecast as of 8am on Thursday, according to the Met Office)
The Met Office also has the following guidance for the yellow weather warning for snow and ice:
Some roads and railways likely to be affected with longer journey times by road, bus and train services
Probably some icy patches on some untreated roads, pavements and cycle paths
Some injuries from slips and falls on icy surfaces