A string of storms have lashed Spain and Portugal this year, examples of extreme weather events that scientists say human-driven climate change is worsening.

Severe weather had already killed five people and injured hundreds in Portugal last week, but Wednesday's deluge left no victims in either country.

Spanish weather agency AEMET placed parts of the southern region of Andalusia under the highest red alert for the "extraordinary" rain dumped by Storm Leonardo, warning of floods and landslides.

The mayor of the city of Ronda, Maria Paz Fernandez, told public broadcaster RTVE that "the ground can no longer absorb" the constant downpours, speaking of "numerous landslides" in the surrounding rural areas.

Andalusia's top emergency official, Antonio Sanz, told a press conference that the situation was "very worrying" in the nearby mountainous municipality of Grazalema.

Grazalema soaked in more than 40 centimetres (16 inches) of rain on Wednesday, "the usual amount of rainfall in Madrid in an entire year", AEMET spokesman Ruben del Campo told AFP in an audio message.

Around 3,500 people had been evacuated in Andalusia, where more than 650 incidents were recorded, none of them causing serious damage, Sanz said, adding that one person was injured in a building collapse.

Spanish police published footage of flooded fields and torrents of water that were engulfing buildings and vehicles.

Hundreds of soldiers deployed to assist the rescue services, while all Andalusian schools were closed apart from in the region's easternmost province of Almeria.

Almost all suburban, regional and long-distance trains were cancelled across Andalusia, with no bus replacement services possible due to the state of the roads, dozens of which were closed.

Spain remains traumatised by its deadliest floods in decades in October 2024, when more than 230 people died, mostly in the eastern region of Valencia.

- 'Situation out of control' -

Leonardo compounded difficulties for Portuguese people already reeling from last week's Storm Kristin, which killed five, injured hundreds and cut off tens of thousands of customers from the power grid.

The emergency services had dealt with more than 3,300 incidents since Sunday, mostly due to flooding, falling trees and landslides, according to the Civil Protection authority.

The service had deployed more than 11,000 people, and around 200 residents were evacuated in central Portugal on Wednesday.

In Alcacer do Sal, south of Lisbon, the Sado river had burst its banks and the rising water had submerged the town's main avenue, AFP journalists saw.

"I had never seen anything like it. Water was pouring into Alcacer with unimaginable force," shopkeeper Jessica Ramalho, 28, told AFP in the town.

Andre Perdigao, a 40-year-old cafe owner, said the town hall was working flat out so that "we can protect ourselves. But right now, the situation is out of control."

The Lisbon region and the Algarve in the south were most affected, with the rain and wind predicted to reach peak intensity overnight Wednesday to Thursday.

burs-imm/sbk