Are there really many students on campus now, in the middle of July?
I stayed one summer in Athens. At that time, I would say in general the vast majority of houses in the student area had at least one inhabitant staying over summer taking classes and/or working. Since the leases run all 12 months, it’s kind of a “might as well” type deal for many. It’s definitely significantly less students than normal, but not a small number by any means. Certainly enough to pack the bars on the weekends, especially when you had other students coming down to visit.
FWIW, I loved my summer in Athens.