The UK is braced for "disruptive snow" as yellow weather warnings cover large parts of the country until Tuesday - with the Met Office saying there is the "potential" for the alerts to be "escalated".
The forecaster has warned up to 20cm of snow may accumulate in the worst affected areas as the country experiences its "first taste of winter".
The Met Office has also told people to expect ice, cold temperatures and wintry showers this week.
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A yellow warning for snow and ice is in place for much of the north of the country - covering areas in the East Midlands, Yorkshire, Wales and the north of England - from 7pm on Monday night to 10am on Tuesday morning.
Those in the impacted areas have been told power cuts are possible and mobile phone coverage might be affected.
The Met Office has said there is a "slight chance" some rural communities could be cut off and that bus and train services may be delayed or cancelled.
People are also warned to be careful not to slip or fall on icy surfaces.
The Met Office has said there will be bright spells across northern and eastern areas throughout today, but rain in the south and west will gradually spread northeastwards and turn to snow over northern hills.
Tom Morgan, Met Office meteorologist, said: "We could see some disruptive snow in the Pennine regions, in particular, the Peak District as well, especially Monday night, but we could well see some impacts lasting on until Tuesday morning's rush hour.
"Even down to lower levels, we could well see some snow as well, so quite a bit of disruption possible by Tuesday morning, and then the week ahead is likely to stay cold nationwide, a windy day on Tuesday, and then winter showers through the week ahead."
Mr Morgan said that despite a "mild" start to the month, the cold conditions are more typical of "mid-winter to late-winter".
"What we can say is that it's going to be very cold for the time of year, there will be widespread overnight frosts, and a few locations where there's snow on the ground," he continued.
Meanwhile, a yellow snow and ice weather warning that came into force at 4pm on Sunday will end at 11am this morning.
The warning covers the northern tip of Scotland and people there have been told there may be icy patches on some untreated roads, pavements and cycle paths.
The Met Office has said there is "potential" for both yellow warnings to be "escalated".
In southern England, a typical maximum temperature for this time of year is 11C (52F), but daytime highs for the week ahead are forecast to be around 5C (41F), while some parts of Scotland will reach "only just above freezing", Mr Morgan said.
The meteorologist said the public can best prepare for the wintry weather by checking their cars are suitable for icy and potentially snowy conditions and to take extra supplies including food, blankets and a fully charged mobile phone with them on journeys.
He added there were "likely" to be changes to the weather warnings in the coming days, and that "winter flurries" could be seen in the south of England later in the week.
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Despite the cold conditions, the "whole of the UK" will enjoy more sunshine this week, the meteorologist added.
He said: "There'll be some snow showers in the peripheries of the UK, particularly northern Scotland, and down the east and the west coast, but if you live inland and you live in the south, there'll be lots of sparkly blue skies on the most days through Tuesday to Friday."
It comes as a cold weather alert issued by the UK Health Security Agency, which was introduced at 9am on Sunday, will be in place until 9am on Thursday.
It covers a large area of England, north of Northhampton. The alert is triggered when there is a risk that healthcare services might face extra pressure and is designed to prepare those who are "particularly vulnerable" and "likely to struggle to cope".
(c) Sky News 2024: UK told to expect 'disruptive snow' as warnings cover large parts of country