For two weeks in August, many of Rome's inhabitants shut up
shop (literally) and go on their own vacations; many stores
and other amenities will be closed during this time. The
temperature in the city centre at this time of year is not
particularly pleasant. If you do travel to Rome at this
time, be prepared to see Chiuso per ferie (Closed for
holidays) signs on many establishments. Anyhow even in these
weeks the city is very beautiful and if you look for a less
overcrowded vacation in Rome this is not a bad time.