Snowstorm Filomena hits Spain and left three people dead on Saturday.
One of these victims is a man found buried in snow in Zarzalejo, north-west of Madrid.
Road, rail and air routes have all been cut and the authorities are asking people to stay at home.
The Minister of the Interior, Fernando Grande-Marlaska asked the population to "postpone any travel by road", while the rescue services and the army snow plows cleared 1,500 trapped motorists.
The minister insisted that "the snowfalls would become icy" in the coming days, temperatures below -10 ° C are indeed expected next week.
According to the latest bulletin from the metrological services, this cold snap will last until Thursday.
Madrid paralyzed
In the capital, "the situation is extremely serious," warned its mayor, José Luis Martinez-Almeida, on Twitter, calling on residents not to leave their homes.
"We are working to clear the access to hospitals as quickly as possible, but it is frankly complicated as long as it snows," said the councilor to the television channel La Sexta.
All schools, from nursery schools to universities, will remain closed Monday and Tuesday, announced the president of the region, Isabel Diaz Ayuso, "while waiting to see the evolution" of the situation.
Parks are closed there, public buses suspended, as is the garbage collection.
Madrid-Barajas International Airport, closed since Friday evening, will keep its doors closed on Saturday for "security reasons".
About 30 flights have already been canceled on Friday and almost as many have been forced to land elsewhere.