Temperatures plummeted again overnight, with Benson in Oxfordshire recording a low of -10C, but in most places the mercury hovered at between -4C and -7C.
We're in the jaws of the Beast From The East - a term forecasters use to describe exceptionally cold air from Russia/Siberia brought in on easterly winds.
In France, where temperatures were forecast to drop to minus 10 C and feel as low as minus 18 C over the coming days, fears ran high for people living on the streets.
On Sunday, a 35-year-old homeless man was found dead in the south-eastern city of Valence, and two days earlier, a 62-year-old man died in his cabin in the woods outside Paris.
The "Beast from the East", as the phenomenon has been dubbed by the British media, is expected to bring chilling winds from Russian Federation over the next week that will make it feel even colder than thermometers indicate.
Residents of the Italian capital woke up on Monday to find their city covered in snow, the unusually freezing conditions prompting some seminarians to launch a snowball fight in St. Peter's Square in Vatican City.More news: Injured Neymar a serious doubt for Real Madrid clash
France has opened up extra emergency shelters for the homeless, and in Calais in northern France, about 200 migrants were spared the cold on Saturday night.
In Belgium, a local mayor in a municipality of Brussels ordered homeless people to be forcibly detained if they refused to go to shelters.
"Tuesday is going to be a very cold day for all of us".
Schools were shut across Kosovo, western Bosnia and much of Albania, as well as in parts of Britain, Italy and Portugal.
Temperatures are plummeting in the United Kingdom and Ireland, where heavy snowfall is causing major travel disruptions.
Berlin is also expected to see temperatures of -20, while Britain is suffering its coldest spell since 1991, according to the Met Office. At least five people died in incidents attributed to the weather.