One man and a woman who were in a auto drowned after a river burst near Malaga in the south, while two homeless people froze to death in Madrid and Calatayud in the east, officials said.
People ski past La Puerta de Alcala during an unusually heavy snowfall in downtown Madrid.
More than 150 roads were still impassable Sunday.
"It (the commute) usually takes me 15 minutes but this time it has been 12 hours, freezing without food or water, crying with other people because we didn't know how we were going to get out of there", said Morena.
Patricia Manzanares had been trapped in her auto on a Madrid motorway since 7pm on Friday.
Spain's weather service forecasts temperatures to drop as low as -14C (6F) in the eastern province of Albacete by Tuesday.
A few courageous people headed out with their ski gear in the Spanish capital.
People walk through snow at Sol Square in central Madrid
Carlos Novillo is Director of the Madrid Security and Emergency Centre.
"The situation remains a high risk". One doctor, Alvaro Sanchez, said on social media he had walked 17km (10 miles) over almost two hours to get to work, while two nurses, Paco and Monica, said they had walked 22km to their hospital.
The country's top coronavirus expert, Fernando Simón, said that he expected the storm's aftermath to impact vaccination plans "in some specific areas", but that overall most doses should still be administered because the priority now remains residents in nursing homes and medical workers.
Aena, which controls the country's airports, said Madrid's Barajas airport, which was closed on Friday night, would remain shut for the rest of Saturday.
Renfe, the state-owned railway company, has also suspended all train services within the capital region as well as all medium and long-distance trains that have Madrid as their point of departure or final destination.
In Toledo, a historic city of 85,000 south of Madrid and capital of the central Castilla La Mancha region, authorities have called for help from the army to clear roads, and prohibited all circulation of vehicles without winter tires or chains.
The storm, through Friday and Saturday, left the capital and large parts of the country under dozens of centimetres (inches) of snow, rarely experienced in Spain, blocking many major roads.
Atletico Madrid's game against Athletic Bilbao which was scheduled for Saturday was postponed, La Liga said in a statement.