Pacific Gas and Electric wanted to wait until high winds had passed and make sure no power lines were blown over or damaged before restoring electricity through them.
Extreme weather events are threatening other Italian regions from Venice, where the MOSE floodgates have been raised to protect the city from high water to Sicily, where heavy storms down trees and flooded homes.
The company is trying to prevent its equipment from starting fires in the dry windy conditions and that can happen if power lines blow over for instance.