Rare 'tsunami' roll cloud phenomenon surprises beachgoers in Portugal

By&nbspEuronews Lisbon

Published on 01/07/2025 – 2:14 GMT+2•Updated
9:21

Mainland Portugal is currently facing a heatwave that has affected most of western Europe, with temperatures reaching 42 degrees Celsius in some regions on the Iberian Peninsula, as well as Greece and France.

The heat produced a variety of unstable weather phenomena in Portugal, including freak rain showers, violent thunderstorms and hail. These phenomena were more intense in the country’s interior.

‘Tsunami’ rolling cloud hits Portuguese beaches

On Sunday, hundreds of sunbathers were surprised by a dense tsunami-like cloud coming out of the ocean and heading towards the beach.

The phenomenon, called a roll cloud, hit several beaches along the Portuguese coast in the afternoon.

The images were widely shared on social media.

Roll clouds are a rare meteorological phenomenon, formed from the interaction of air masses of contrasting temperatures and sea breezes.

These clouds are tube-shaped and move horizontally. Despite the clear resemblance to a giant wave, thankfully, they have nothing to do with tsunamis.

As the clouds approached, strong winds appeared, taking bathers by surprise.

As temperatures continue to rise throughout the week, concerns about major forest fires are intensifying.

The National Civil Protection Authority has issued a warning to the population with preventative measures and other recommendations.

The communiqué states that the danger of rural fires is very high to maximum in the interior of the north and centre and in the Algarve.