Yellow weather warnings are in place as the Met Office warns of “significant disruption” to transport and power supplies amid the arrival of Storm Larisa.
Warnings for snow and ice have been issued in London and the southeast, southwest England, the East Midlands and the East of England.
They are in place from 4am on Friday and until 10am the same day.
Another alert was also issued for Wales.
The Met Office said: "Periods of rain will likely transition to snow from the northwest, continuing east and south through Friday morning easing as it does so.
"A few centimetres of snow is likely in places, with 2-4 cm possible across parts of Wales, and perhaps higher ground elsewhere such as the Cotswolds.
"Icy surfaces also likely to develop."
Laris is to bring “treacherous conditions” to the UK on Thursday night and Friday morning, the weather boffins said and 50mph winds and 40cm of snow is forecast in some areas.
Met Office meteorologist Jonathan Vautrey said the storm, which has been named by the French weather service, is bringing rain and snow to the UK.
“Storm Larisa, which Meteo France have named, is the same low-pressure system that is bringing us the bands of rain,” he said.
“But essentially, we’re on the northern side of the low pressure system and it’s the southern side of that low pressure system that is going to be bringing particularly strong winds to parts of France.
“So that did originate out in the Atlantic and then it tracked its way eastward towards us, and the weather fronts that are swirling around that low pressure system have then been pushing into the cold air that has been in places across the UK and allowing that rain to start falling as snow across several areas.”
The affected areas are as follows:
East Midlands
- Lincolnshire
- Northamptonshire
- Rutland
East of England
- Bedford
- Cambridgeshire
- Central Bedfordshire
- Hertfordshire
- Luton
- Peterborough
London & South East England
- Buckinghamshire
- Milton Keynes
- Oxfordshire
- West Berkshire
South West England
- Gloucestershire
- South Gloucestershire
- Swindon
- Wiltshire
Wales
- Blaenau Gwent
- Caerphilly
- Merthyr Tydfil
- Monmouthshire
- Neath Port Talbot
- Powys
- Rhondda Cynon Taf
- Torfaen
Amber warnings for snow were already in place until 12pm on Friday in the East Midlands, Yorkshire and the Humber, West Midlands, northeast England and the northwest.
Wales and Northern Ireland also have amber warnings for snow and ice in place until 9am and 4am respectively.