Dozens of people moved to emergency shelters in Mouries and Saint-Martin-de-Crau — two small towns between Montpellier and Marseille — and at least one person was injured, officials said, Reuters reported.
Roads and train lines in the area were disrupted, Transport Minister Philippe Tabarot wrote in a post on X.
Forecasters said the weather would settle down in the south.
But Storm Austen was expected to bring heavy winds across the northwest later on Thursday into Friday, weather agency Meteo France said.