Grid operator Enedis said 300,000 homes were without electricity Friday, mainly in the Drome, Ardeche, Isere and Rhone departments, which include the cities of Lyon and Grenoble, a spokesman told BFM television.
"It's an exceptional situation because the snow is heavily concentrated in a single area, which is why we have significant damage to our power lines," said the spokesman, Robin Devogelaere.
"We've had trees knocked down, and branches weighed down with snow have frozen and caused short-circuits," he said, adding that treacherous roads were making it hard for teams to reach and fix the cables.