Cold health alerts have been issued for large parts of the UK from midday on Monday until Saturday morning.
The UK Health Security Agency (UKHSA) issued an amber cold health alert for the North East, North West and Yorkshire and the Humber on Monday.
A yellow cold health alert affects the rest of England.
Check the weather forecast where you are
Snow and ice are possible, the Met Office said, as a spell of above-average temperatures comes to an end.This breaking news story is being updated and more details will be published shortly.
Temperatures dropped as low as minus 7C (19F) in Tulloch Bridge in the Highlands on Saturday, the UK's coldest night since March.
Met Office deputy chief meteorologist Dan Holley said: "As Storm Claudia retreats to the south, high pressure to the North West will drive a cold northerly flow from the Arctic across the UK."
Mr Holley predicted "much colder conditions than of late and, whilst generally drier than recent days, there will also be a risk of wintry hazards, such as snow and ice".
Widespread frosts are likely across the UK, he said, with temperatures dipping "as low as minus 7C in places".
Single-figure daytime temperatures, coupled with a brisk northerly wind, will mean "a marked wind chill".
An amber warning means the weather is likely to cause "significant impacts across health and social care services" including an increase in demand for health services, temperatures inside places like hospitals, care homes and clinics dropping below the levels recommended for assessing health risks and a rise in deaths, particularly among those aged 65 and over or with health conditions.
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