Literally. They've all gone away. That's right, Belgians have packed their bags and left. This is, traditionally, the month everyone chooses to have off. Not just for a couple of weeks, but the whole month. Half of my students are away, and the other half will be taking all of August off.
It's not uncommon to wander around Mons and see shops, hairdressers, restaurants, with signs saying they are closed for a 2, 3, or 4 week period.