Hmm. Actually, ”le vent des fous” seems to be referring to a wind from the south, supposedly bringing in heat and humidity from the Mediterranean.

https://en.wikipedia.org/wiki/Valence,_Drôme#Climate

Valence enjoys a humid subtropical climate, whose main characteristic is an almost constant wind …. When it comes from the south, it usually announces the arrival of stormy disturbances. It is then called le vent du midi ou le vent des fous [the midi wind or the uncaring wind] because, for some people, it makes the atmosphere painful to bear, especially in the summer.