Wintry conditions are affecting large parts of the UK, with snow and ice and heavy rain from northern Scotland to the southern counties of England.
Met Office yellow “be aware” warnings are in place for Scotland, north Wales, most of England and Northern Ireland.
Temperatures fell sharply on Saturday night, with a low of -13.5C (7.7F) in the Highlands village of Dalwhinnie.
In north Devon, several homes have been evacuated after “widespread flooding” sparked by heavy rain.
The Met Office warning of snow and ice is valid from 06:00 GMT until 18:00 GMT and predicts snow on higher routes and says rain may fall onto frozen surfaces for a time, particularly across Scotland.
The alert, originally issued on Saturday, was later extended northwards to cover the northwest Highlands, parts of the Western Isles and southwards to cover more of Hertfordshire, Essex and Suffolk.
The Met Office chief forecaster said the amounts of fresh snow would vary considerably across the warning area, with 3-6 cm possible on higher ground and 1-3 cm at lower levels, although some spots would not see any.
Drivers in south-west Scotland were urged to “avoid unnecessary journeys”.
Police said heavy snowfall across Dumfries and Galloway was causing problems on roads including the A75, which was blocked just outside Dumfries for a time.
Meanwhile, two climbers were airlifted to safety after being discovered in a “precarious position” on a mountain ridge in Glencoe since Friday.
The pair had survived a night without shelter in sub-zero temperatures after becoming stuck at 3,000 ft at Bidean nam Bian.
Blizzard conditions had prevented a mountain rescue team from reaching them.
In Wales, Met Office warnings are in place for Wrexham, Conwy, Denbighshire, Gwynedd, Powys and Flintshire. Up to 6cm (2.3in) of snow is forecast to fall on ground above 200m (656ft).
Snow is affecting driving conditions on the A470 between Betws-y-coed and Blaenau Ffestiniog. The M4 motorway was partially closed near Bridgend after a serious accident involving an overturned car.
South Wales Police urged motorists to avoid travelling, saying driving conditions were hazardous with spray and standing water on the road.
A Met Office warning of rain is in place for central and southern Wales and north Devon.
Police in Devon said properties in Kentisbury, near Barnstaple, and Combe Martin on nearby Exmoor, have been affected by the conditions.
The A399 at Combe Martin has been closed following a landslide, while the A361 is also shut near Landkey in Barnstaple.
Are you in an area affected by the adverse weather? If it is safe to do so, please share your experiences by emailing firstname.lastname@example.org.
Please include a contact number if you are willing to speak to a BBC journalist. You can also contact us in the following ways: