A blast of Arctic air is set to send the mercury plummeting with a cold snap lasting into next month.
Forecasters have warned that snowfall is possible across the country but is most likely to fall in northern parts.
The Arctic blast is expected to take hold later on Wednesday, with the Met Office saying it could be a “shock to the system”.
Met Office meteorologist Marco Petagna said: "Things are turning colder, but it is just more typical winter conditions.
"It has been so mild this winter that it will be a bit of a shock to the system even though temperatures will be average for this time of year or just below."
He continued: "Certainly we could start to see some sleet and snow showers across the higher ground of Scotland."
Northern parts of Scotland and the east of England could also see some snow showers over the course of Wednesday, although it is unlikely to settle.
"It's nothing unusual, but it's the first wintry weather that some parts of the UK have seen for a while," he said.
The temperature will continue to fall going into Thursday, leading to a widespread frost.
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"There won't be too much in the way of snow accumulation, although some of the higher ground of Scotland could see several centimetres," Mr Petagna said.
Elsewhere, the Met Office expects to see a few icy patches but nothing that was expected to cause any real issues to public safety.
However, things could get quite a lot colder at the beginning of next week.
"There's quite a lot of uncertainty about how things will play out," Mr Petagna said.
