PERILS, the independent Zurich-based organisation that provides industry-wide catastrophe insurance data, has released its second industry loss estimate for extratropical windstorm "Nils," also known as "Ulrike."
The system affected the Nouvelle-Aquitaine and Occitanie regions in southwest France from Feb. 11 to 13, bringing extreme winds and flooding.
PERILS now puts the insurance market loss from Windstorm Nils at €767 million, up from its initial estimate of €586 million issued last March, and six weeks after the event end date. The figure is based on loss data collected from affected insurers and covers the property and motor lines of business.
The loss estimate forms part of PERILS' industry loss index service, which supplies independently validated loss data for natural catastrophe events to support insurers, reinsurers and ILS investors with model validation, portfolio analysis and index-based risk transfer.
Windstorm Nils was described as a very intense extratropical cyclone, with maximum gusts strong enough to cause widespread damage across parts of south-west France over the three-day period.
According to PERILS, wind was the primary driver of the insured loss, although the storm also produced significant flooding in the affected regions. On current figures, Nils represents the largest individual event loss of the 2025/26 European windstorm season, with wind damage accounting for most of the industry bill.
For the French market, Nils adds to the burden on the country’s natural catastrophe regime (CatNat), under which a compulsory extension to property insurance is backed by state-supported reinsurer Caisse Centrale de Réassurance (CCR), which benefits from an unlimited state guarantee for natural disaster losses.
CCR has indicated that total damages from Nils alone could reach around €1 billion, and France Assureurs and CCR together have put losses from tempests Nils and Pedro at about €1.2 billion, underlining the wider economic impact beyond the PERILS-defined market segment.
Nils also generated additional secondary perils in other parts of France, including the Alps.
Media reports highlighted widespread power cuts, transport disruption and major river flooding in western and south-western France as Nils moved through, prompting high-level warnings from Météo-France and large-scale civil protection mobilisation. For insurers and reinsurers, the event underlines the complexity of European winter storms, which can generate concurrent wind, flood and avalanche losses under multiple policy types, testing both operational claims capacity and assumptions around correlation between perils.
“Storm Nils was a multi-hazard natural catastrophe which not only brought damaging winds and flooding to southwest France but also caused avalanches in the French Alps," said Luzi Hitz, product manager at PERILS. "While it challenged the civil protection services, the fact that there were only two fatalities demonstrates the effectiveness of their response.”
Despite Nils, Hitz noted that overall European windstorm activity in 2025/26 has remained subdued in loss terms.
Goretti, also known as "Elli," affected southwest England, northern France and Belgium from Jan. 8 to 9 and currently ranks as the second-largest loss of the season, with PERILS putting its market loss at €479 million in its second estimate. Recent analysis has characterised both the 2024/25 and 2025/26 European windstorm seasons as relatively benign from an industry loss perspective, despite several named systems tracking across the continent.
As the market digests the detailed CRESTA-zone footprint for Nils later this year, attention is expected to focus on how well current catastrophe models captured the multi-hazard nature of the event and whether further adjustments are needed to vulnerability, correlation and flood components for south-west France.
The PERILS data will feed into those technical discussions, as well as into renewal negotiations for French and pan-European property catastrophe programmes ahead of Jan. 1, 2027.
