Photos and videos continue to pop up online from the major power outages on Monday in Portugal, Spain, and parts of France.

Why It Matters

More than 50 million citizens across Portugal and Spain were affected by the general blackout that began around 12:15 p.m. local time in Spain on Monday.

The impact was felt immediately as vehicles became caught in traffic jams without operational lights; trains and subways stopped moving; telephone lines and mobile networks went down; card payment machines stopped functioning; and even a major tennis tournament, the Madrid Open, was halted.

Spain’s busiest airport in Madrid lost electricity, while other major cities, including Barcelona, Seville and Valencia, lost power.

What To Know

REN, Portugal’s grid operator, attributed the outage in Spain’s electric grid to a “rare atmospheric phenomenon.”

Temperature variations in the country led to “anomalous oscillations” in very high-voltage lines, REN said. Temperatures as of 7 p.m. local time in Spain remained as high as 70 degrees.

“Due to extreme temperature variations in the interior or Spain, there were anomalous oscillations in the very high voltage lines (400 KV), a phenomenon known as ‘induced atmospheric vibration,'” REN said.

“These oscillations caused synchronization failures between the electrical systems, leading to successive disturbances across the interconnected European network.”

Spain’s Red Eléctrica said at the outset of the outage that national electricity demand plummeted from 27,500 megawatts to 15,000 megawatts.

While video footage shared by RTVE, Spain’s public broadcaster, showed evacuations from metro stations and halted trains in Barcelona, Portugal’s National Authority for Emergencies and Civil Protection confirmed that backup power systems, including generators, were swiftly activated to allow hospitals and emergency services to continue operating.

Spanish Prime Minister Pedro Sánchez thanked the French and Moroccan governments for helping to restore power to northern and southern Spain, according to the Associated Press.

The Portuguese National Cybersecurity Center stated that there was no indication the outage was due to a cyberattack.

In Terrassa, an industrial town about 50 kilometers (30 miles) from Barcelona, stores ran out of generators for the public, per the AP.

The outage comes less than two weeks after Red Eléctrica confirmed that renewable energy sources fully met electricity demand across Spain’s grid for the first time on April 16, according to PV Magazine in Spain.

It was a first for the country, which combined wind and photovoltaic (PV, or solar) power to generate 100.63 percent of total demand, and on a weekday, which was also new.

What People Are Saying

Madrid Mayor José Luis Martínez-Almeida said: “I ask all residents of Madrid to keep their movements to an absolute minimum and, if at all possible, to remain where they are. We want to keep all roads clear.”

Portuguese electricity distributor E-Redes blamed the blackout on a “problem with the European electricity system,” according to local newspaper Expresso. The company said it had to deliberately cut power in some areas to stabilize the grid.

What Happens Next

By mid-afternoon local time, Spain’s Red Eléctrica reported a gradual recovery in the country’s northern and southern regions. Portuguese distributor E-Redes, which initially blamed the blackout on a “problem with the European electricity system,” confirmed that power was being progressively restored across Lisbon, Porto, and other major cities.