The first snowfalls of the season have seen travel disrupted and some schools closed as parts of the UK experience the first wintry weather of the season.
There are currently three yellow warnings in place for snow and ice in Northern Ireland, northern Scotland, northern England, the Midlands and north-east Wales.
Some 130 schools in the Powys, Wrexham and Flintshire areas of Wales as well as around 50 in the West Midlands and 19 in Derbyshire have closed due to the weather. National Rail said various Northern services could be affected until at least 14:00 GMT.
Freezing temperatures on Tuesday night could lead to icy roads and pavements on Wednesday, BBC Weather said.
BBC Weather reported that 12cm (5in) of snow had fallen in Nottingham, with the East Midlands one of the areas subject to a Met Office warning - along with Yorkshire and the North - until 11:00 GMT.
A new yellow warning has been issued for Northern Ireland which comes into effect at 18:00 on Tuesday evening and lasts until 10:00 on Wednesday. There is also a warning for snow in northern Scotland until 10:00 on Wednesday.
The north of Scotland experienced the coldest temperatures since last winter overnight, with minus 7.8C logged in Tulloch Bridge in the Highlands.
BBC Weather's Helen Willetts said that after the first snow of the season for many, warnings are now being issued about the ice risk through Tuesday evening and overnight.
Snow showers will also continue, giving several more centimetres across the northern half of Scotland with a scattering developing in Northern Ireland.
Wintry showers elsewhere combined with wet surfaces will add to the ice risk and conditions could become treacherous on untreated roads and underfoot as a widespread frost is forecast overnight, Willetts added.
Temperatures in the coming days will be much lower than the mid-November average by day - and are expected to reach below freezing by night.
They are predicted to drop to -2C in London on Friday, -4C in Birmingham and -7C further north.
The RAC said Tuesday's snow was the "first taste of winter" for many drivers with "some of the worst road conditions we've seen all year".
Spokesperson Alice Simpson said: "Everyone should travel prepared in case they find themselves broken down at the side of the road: a blanket, warm waterproof coat and gloves, sturdy footwear and a charging cable and mobile power bank are all essentials.”
The UK health security agency (UKHSA) has said there is an increased risk to vulnerable people, warning the weather could have an impact on the whole health service.
It has issued an amber cold weather health alert for the East Midlands, West Midlands, North East, North West and Yorkshire and the Humber.
“It is vital to check in on vulnerable friends, family and neighbours to ensure they are well prepared for the onset of cold weather. Particularly if they are elderly or otherwise at increased risk,” Dr Agostinho Sousa, head of extreme events and health protection at UKHSA, said.
BBC Weather says forecasting snow is difficult at lower levels, especially in mid-November when the ground and surrounding seas are still relatively warm compared to midwinter.
By this coming weekend, forecasters are expecting the cold air to be replaced by milder south-westerly winds - with potentially wet and very windy weather sweeping in.
As the wetter weather moves northwards there remains the risk of some snow, before it quickly thaws.