Snowfall disrupts northern Europe's airports and roads
In Poland, eight homeless people died as temperatures fell below -20C (-4F).
Airports were closed in the UK, France and Switzerland. Dozens of flights were affected in Germany and Spain.
Prominent figures including Spanish Prime Minister Jose Luis Rodriguez Zapatero faced delays as they headed to Zurich for the Fifa World Cup vote.
In the Russian capital, Moscow, temperatures dropped to -23.6C (-10.5F), the lowest on record for 1 December since 1931.
In Poland it was even colder, with the eastern city of Bialystok registering temperatures of -26C (-14.8).
Police in the country appealed to the public to get in touch if they found any homeless people living outdoors after eight homeless men were found frozen to death.
In Britain, thousands of schools were closed and police in the southern county of Surrey described conditions as the worst they had ever seen.
The Met Office has issued heavy snow warnings for much of the eastern side of Britain and some central areas.
There were severe flight delays reported in Frankfurt, Munich, Vienna and Prague.
In France, 12 regions in the frozen east and centre banned the use of lorries, forcing more than 7,000 of them to park overnight.
Thick snow across Germany blocked roads, and caused flight cancellations and school closures. Bild newspaper said it was the coldest start to December for centuries, with some areas reporting temperatures as low as -18C (-0.4F).
Increased demand for gas and electricity saw a rise in prices on Europe's energy markets.
Rome's Tiber river came close to overflowing in parts after water levels rose by more than a metre in one day.
In Albania, meanwhile, a state of emergency was declared due to widespread flooding along the Drini River delta north-west of the capital, Tirana.