Rare Summer Swell Triggers Beach Evacuations & Coastal Alerts Across France
Biarritz, France – August 26, 2025 – A powerful and unusual cyclonic swell, born from the remnants of ex-Hurricane Erin, is unleashing dramatic waves along France’s Atlantic coastline, forcing beach evacuations, prohibiting swimming, and raising concerns about coastal erosion. This isn’t your typical summer scene on the French Riviera; authorities are bracing for potentially dangerous conditions through Friday, a stark reminder of the ocean’s raw power even during the warmest months.
Unseasonal Waves & Coastal Vigilance
Météo-France reports waves exceeding 6 meters (nearly 20 feet) off the coast of Finistère, with significant swells also impacting Noirmoutier (Vendée), Cap Ferret (Gironde), and Saint-Jean-de-Luz (Pyrénées-Atlantiques). While swells of this magnitude are common in winter, their appearance in late August is decidedly atypical. “These are quite common things in winter, less for this period of the year,” explained Christelle Robert, a forecaster with Météo-France. The phenomenon isn’t a direct cyclone impact, but rather a strong swell propagated by the storm’s energy across the Atlantic.
Six departments – Côtes-d’Armor, Finistère, Charente-Maritime, Gironde, Landes, and Pyrénées-Atlantiques – are under yellow vigilance for wave-submersion, indicating a potential for flooding and hazardous conditions. The peak of the swell is expected to coincide with high tide between 7:00 p.m. and 8:00 p.m. in New Aquitaine, amplifying the risk of coastal inundation.
Biarritz & Beyond: Beaches Closed, Safety Measures in Place
The popular resort town of Biarritz has taken swift action, hoisting red flags prohibiting swimming and evacuating its central beach and adjoining promenade. Thousands of vacationers, enjoying the last week of school holidays, were urged to leave the area as waves crashed against the shore. For the first time in summer, sandbags have been deployed to protect the casino and municipal swimming pool, a testament to the seriousness of the situation. “This is the first time that this submersion waves device has been deployed in summer,” stated Michel Laborde, Biarritz’s deputy mayor in charge of the coast. “And it is therefore the first time that we have faced as many people to manage.”
Similar precautions are being taken in Lacanau, Mimizan, and Biscarrosse (Landes), where swimming and certain nautical activities have been banned. Lifeguards are actively patrolling beaches, using vehicles and loudspeaker announcements to ensure public safety. A maximum alert for “bains,” dangerous ripping currents, is also in effect along the entire southwest coastline.
The Long-Term Threat: Coastal Erosion & Climate Change
This event isn’t just a short-term disruption; it highlights the growing vulnerability of France’s Atlantic coast to erosion. The region is already experiencing significant land loss due to wind, waves, and tides, and this trend is accelerating. The Arguin sandbank, a four-kilometer stretch of sand at the entrance to the Arcachon basin, is particularly at risk. Benoît Dumeau, curator of the nature reserve, warned that the powerful waves could inflict significant damage to this fragile ecosystem, a vital nesting ground for numerous bird species.
Experts believe that climate change is exacerbating coastal erosion, with rising sea levels and more frequent extreme weather events contributing to the problem. While natural coastal processes are always at play, the intensity and frequency of these events are increasing, demanding proactive measures to protect vulnerable communities and ecosystems. Understanding these risks is crucial for coastal management and long-term sustainability.
As the swell continues to impact the French Atlantic coast, authorities are urging sea users to exercise extreme caution and heed all warnings. The emergency number for sea rescue is 196. This unusual summer swell serves as a powerful reminder of the ocean’s dynamic nature and the importance of respecting its force, even – and especially – when the weather seems deceptively calm. Stay informed with the latest updates from Archyde as this situation develops.