Swiss catastrophe modeller Perils estimates Windstorm Nils led to €586 million ($983.48 million) of insured losses, in its first of four assessments on the damage.

Its report, coming six weeks after the storm hit southwest France, examines property and motor losses only.

Nils, also known as Windstorm Ulrike, was among a series of storms that hit France in late January and early February amid the region’s wettest start to a year since record-keeping began in 1959.

It left more than 900,000 homes without power, and extreme wind was the primary cause of losses.

Nils also caused flooding in the Garonne, Dordogne and Charente river basins, and avalanches in the Alps.

Perils product manager Luzi Hitz says Nils was the region’s most significant windstorm since Klaus in January 2009, and the two bore a “striking resemblance” in wind patterns.

But Nils was not “an extraordinary event on a European scale”, and such losses are expected at least once a year.

“Klaus caused an industry loss of €1.57 billion ($2.63 billion), while for Nils, losses were lower due to less intense wind gusts,” Mr Hitz said.

“Nevertheless, it represents a sizable event for the French insurance market and follows only a little over a month after Windstorm Goretti, which also significantly impacted France.”

The loss figures do not include those related to Storm Pedro, which struck the same region a week later but fell outside the “prevailing 72 hours clause for storm event definition for reinsurance purposes in France”.

Perils will give an updated estimate on Nils’ insured losses on May 13.