How the April 28, 2025, power outage in Portugal and Spain impacted Internet traffic and connectivity

Cloudflare analyzes a large power outage on April 28 (10:34 UTC) impacting Portugal and Spain, showing immediate national traffic drops (~50–60%) that deepened over hours, sharp declines across major ISPs/ASNs, regional disruptions, degraded performance (median download speeds falling to ~15–19 Mbps; latency rising to ~40–50 ms), and significant reductions in announced IPv4/24 and IPv6/48 prefixes as infrastructure lost power. Some recovery is noted in parts of Spain per Red Eléctrica updates; France and Andorra saw nominal or no regional impact, while Orange Maroc experienced disruptions later. The findings illustrate how grid failures drive congestion, routing shrinkage, and connectivity loss, with recovery tracking power restoration.