Colder conditions bring to an end a run of unseasonably mild weather over the festive period, which saw highs of between 11C and 13C on Christmas Day.
Temperatures are set to be around 5C below the early January average, with a wind chill making it feel even colder.
Amber cold health alerts cover the whole of England but are not in place for the rest of the UK.
The UK Health Security Agency (UKHSA) issues the alerts when adverse temperatures are likely to impact on people’s wellbeing, in particular those who are elderly or have health conditions. The alerts provide early warning to healthcare providers.
A yellow warning for ice is in place across north-west England, western Scotland and Northern Ireland from 17:00 GMT on Thursday until Friday morning as temperatures drop through the night.
The Met Office also warns of snow in north-east Scotland, including the Orkney and Shetland Islands, into Friday.
The larger snow and ice warning starts at noon on Saturday until midnight, and covers all regions of England apart from the south-west, and the majority of Wales.
Most of Scotland is covered by a separate snow warning from midnight on Sunday until 12:00 GMT on Monday.
Saturday is likely to be the coldest day as most areas will see top temperatures of around -1C to 2C. There will be overnight frosts in the coming nights too.
While we are now in a chillier spell with wintry showers and potential for significant snow over the weekend for some, this is nothing unusual for winter in the UK.
Age UK’s director Caroline Abrahams said the cold weather would bring the government’s decision to limit winter fuel payments “into sharp relief”, and added that the charity had already been contacted by people “worrying about what to do”.
“We urge older people to do everything they can to stay warm, even if that means risking spending more on their heating than they feel they can afford,” she said.
“The energy companies are under an obligation to help if you are struggling and there may be support available from your local council too. Better that than to jeopardise your health.”
The prime minister previously said it was important to protect pensioners who most needed the allowance, but many did not need it because they were “relatively wealthy”. The cut aims to save £1.5bn a year.
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