Police and fire-officers in the region around Nantes received more than 300 calls, mainly for flooding and fallen trees.
A container ship carrying timber came aground on the Ile de Re after losing power during the storm, and 20 of its 26 crew were taken off by helicopter. A navy tug was preparing to tow it back to sea with the tide.
Forecasters said the storms were heading northeast, passing to west of Paris and steadily losing force.