AEMET said the alert level in Valencia was cut by two levels from red -- its highest -- to yellow, a day after torrential downpours forced schools across the region to close.

By contrast, Ibiza and Formentera were placed under red alert, with forecasters warning of "extraordinary danger" from heavy rainfall that could trigger flash floods and river surges in the Mediterranean islands.

Ibiza City, the capital of Ibiza, urged residents to avoid travel and outdoor activities and warned in a post on X against approaching streams, low-lying areas or basements.

Monday's red alert in Valencia revived memories of October 2024, when flooding killed more than 230 people.

More than half a million pupils in Valencia missed lessons on Monday as 243 local councils closed schools as a precaution.

Images on social media showed roaring torrents of water gushing through the town of Cullera, south of the regional capital Valencia, one of the hardest-hit areas.

Cullera Mayor Jordi Mayor said residents' compliance with calls to stay indoors "prevented many tragedies."

"If there had been an elderly person, someone with mobility difficulties, or even children out on the streets, the consequences could have been much worse," he told Spanish public television.

Last year's disaster sparked public anger over the adequacy of warning systems and the emergency response. Residents have continued to stage protests, accusing officials of failing to provide timely alerts.