A significant power failure impacted Spain and Portugal on Monday, disrupting traffic signals and necessitating subway evacuations in both nations, among other issues. The cause is attributed to a “rare atmospheric phenomenon,” according to reports.

Data from Spain’s electricity network website indicated a sharp decline in power demand around 12:15 p.m. local time, dropping from 27,500 megawatts to nearly 15,000, the Associated Press reported. 

According to REN, Portugal’s grid operator, “Extreme temperature variations in the interior of Spain caused anomalous oscillations in the very high-voltage lines, a phenomenon known as induced atmospheric vibration.” They added, “These oscillations resulted in synchronization failures between the electrical systems, leading to successive disturbances across the interconnected European network.”

REN reportedly characterized the event as a “rare atmospheric phenomenon.” The Portuguese National Cybersecurity Center stated that there was no evidence of a cyberattack being the cause. 

Spanish television footage showed evacuations from metro stations in Madrid and deserted stations with closed gates in Barcelona. Spain’s parliament was also affected by the blackout, according to public broadcaster RTVE. 

The play at the Madrid Open tennis tournament was halted due to the power interruption. 

In Portugal, several Lisbon subway trains were evacuated, court proceedings were suspended, and ATMs and electronic payment systems experienced issues. Traffic lights in Lisbon also ceased functioning. 

Spanish airports were relying on backup power systems, and some flights experienced delays, according to Aena, the operator of 56 airports in Spain, including those in Madrid and Barcelona.

Lisbon Airport’s website warned that “A general power cut may cause operation constraints” and advised travelers to “Contact your airline before heading to the airport.”

Both the governments convened emergency cabinet meetings to address the situation, according to Reuters. Residents in both countries reported observing panic buying of water and other supplies in supermarkets.

Spanish Prime Minister Pedro Sánchez visited grid operator Red Eléctrica to monitor power restoration efforts. 

Eduardo Prieto, head of operations at Red Eléctrica, described the event as unprecedented, calling it “exceptional and extraordinary.”

“Voltage has now been restored at substations in several areas of the north, south, and west of the Iberian Peninsula,” Red Eléctrica posted on X. “This process involves the gradual energization of the transmission grid as the generating units are connected.” 

“The causes are being analyzed, and all resources are being dedicated to addressing the issue,” they added. 

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