Google ‘the best and worst times to visit Italy’ and just about every source you find will tell you that the best months to visit Italy are April through June and September through October and that the worst times to visit are July and August, when the weather gets uncomfortably hot and high season brings high prices and crowds.
Terrific tips here! I love that after dark Colosseum tour. (and Pigneto is pretty great for the adventurous traveler)
My parents just got back from Napels and Amalfi and Rome area. They were told it had never been so crowded at this time of year. Crowds are intense at the moment.
Ah, Puglia! Brilliant place to visit. I'd also suggest Matera!