Spain is known for its good weather, long sunny days and sandy beaches. But if you’re going to enjoy the beaches of northern Spain, you should be aware of the risk of galernas.

A galerna is a meteorological phenomenon characterised by sudden stormy conditions with strong winds that cause temperatures to plummet by up to 20C in a matter of hours.

Geographically speaking, these sorts of storms happen on Spain’s northern coast and generally batter areas along the Cantabrian Sea and the Bay of Biscay including the coastal regions of Asturias, Cantabria, the Basque Country as well as parts of southwestern France.

READ ALSO: Weather in Spain: What is ‘calima’ and is it bad for you?

Etymologically the word galerna has its origins in the French galerne which comes from the Breton gwalarn, meaning strong winds from the northwest.

A galerna usually appears without warning, making them particularly dangerous for boats at sea as well as being a bit of a shock for unprepared beachgoers relaxing in the sun.

Ayer 42°C ☀️
Hoy 22°C con sirimiri 🌧 pic.twitter.com/vpw3ygQcvu

— tiempo/Donosti (@TiempoDonosti) August 12, 2024

They tend to happen when, in a place where there are warm southerly winds, cold and humid north-westerly winds suddenly sweep in. This causes strong gusts of wind and a sudden drop in temperatures, which can fall by as much as 10 or even 20C in the space of a few hours.

There were galernas very recently in Spain on both the Cantabrian and Basque coasts, where a huge and sudden drop in temperatures was felt in the area, especially in San Sebastián, where the mercury plummeted by 17C with thermometers dropping from 42 to 25C.

The biggest temperature drop, however, was in the Cantabrian town of Tama, which went from 43.1 to 25C — a drop of 18.1 degrees.

One Twitter/X user uploaded some pictures of a galerna in Gijón to show just how quickly these things occur and the extent to which the weather conditions change.

User javif_4 stated: “San Lorenzo Beach, Gijón. – Left: at 18:00 heat and no wind. – Right: Two hours later, strong winds that are getting stronger, temperatures dropping and waves increasing.” 

Playa de San Lorenzo, Gijón.
– Izquierda: a las 18:00 calor y nada de viento.
– Derecha: Dos horas después, viento fuerte que va a más , bajón térmico y aumento del oleaje. #GALERNA@slaplana_tve @mbarreiro_tve @Nuria_Sero @aquilatierratve @ElTiempo_tve pic.twitter.com/aRCzJaFoj1

— Javi (@javif_4) August 11, 2024

The galerna in Gijón shows a pretty stark change in the weather, but fortunately it wasn’t strong enough to cause any real damage or kill anyone, as some of the worst galernas have over the years.

As mentioned above, galernas are particularly feared by fisherman and sailors for their extremely sudden and violent change of conditions. Several galernas have claimed the lives of fishermen over the years.

Perhaps the worst of all occurred in April 1878. It became known as La Galerna del Sábado de Gloria and was famously immortalised by Cantabrian novelist José María de Pereda in his novel Sotileza.  

Owing to the sudden galerna that unexpectedly blew in that day, a staggering 322 fishermen drowned in the Cantabrian Sea, including 132 Cantabrians and 190 Basques. Over 500 boats were sunk. The incident caused quite a stir around the rest of Spain, it led to improved navigation and rescue protocols, and was a big blow to local families and economies.

Other notable galernas happened in 1912, 1914, 1961, 1987 and 2002.