Power cuts hit some 13,000 homes in the Somme on Friday evening and 5,400 were still without electricity at midnight, according to power company ERDF.
A pylon serving the area was put out action by summer storms that hit much of the Channel coast and north-west of the country.
Emergency services were called out to 152 times in the Somme on Friday evening, mostly to tackle floods and mudslides and evacuate old people's homes that appeared to be in danger of flooding.
In the neighbouring Nord they were called out 222 times, although generally for minor incidents such as tree blown over and power cables downed by the wind.
Storms were forecast for Saturday in the Massif Central, the Rhône valley, the Alps and the Pyrenees.
Elsewhere the sun was expected to continue to shine but temperatures to fall by some 10°C in Paris, which sweated under 30°C on Friday, Lille, Rennes, Nantes, Bordeaux and Toulouse.