Winds gusting to hurricane force left nearly 70,000 homes in western and northwestern France without power Sunday, the national electricity grid Enedis said.
The national weather agency Meteo France said winds powering to 160 kilometres (100 miles) per hour battered the Breton peninsula and Normandy coast overnight, and two other regions remained under a storm alert.
Enedis said 33,000 homes were without power in Normandy, 18,700 in Brittany and 16,500 in the Loire-Atlantique region, which lies south of Brittany.
A woman was seriously hurt in Brittany's Cote d'Armor department when her car hit a fallen tree, local officials said.
The fire brigade in Brittany was called out more than 600 times during the night, mainly to clear blocked roads, they said.
Meteo-France said storm conditions in the northeastern Atlantic had combined with a strong airstream directed at northwestern France, producing "an event that occurs three or four times per year."
The agency maintained a high-winds alert for three departments -- the rough equivalents of counties -- in the northwest, and for three in the centre-east. The winds were expected to die down on Monday.