How do you say whole month in french?

The most common and natural way to say "whole month" in French is "tout le mois".

Here are some examples:

* J'ai travaillé tout le mois. (I worked the whole month.)

* Il a plu tout le mois de juin. (It rained the whole month of June.)

* Je vais être en vacances tout le mois d'août. (I'm going to be on vacation the whole month of August.)

You could also say "le mois entier" (the whole month) or "tout au long du mois" (throughout the whole month), but they are less common.