Italy in June or July

July will be HOT, June less so.

I would go as early in June as possible for lower crowd volume and less heat.

What is your criteria? I can comment on the climate: It's going to be hotter in July so if you want to see any of Southern Italy, I recommend June. As early as possible. We were there end of May/early June last year and it was HOT (sunny, high 80s in Florence), but it got even hotter later that summer (90s and above).

Personally, I'd avoid going anytime in July or August. May is better than June, but if you must go in June, I'd go as early in June as possible.

I think it depends on your needs. We went last summer in July and couldn't go in June due to kids schedules. It was, as other posters have mentioned, quite hot. This was not a problem for us as we knew ahead of time, picked lodging that had air conditioning and carried lots of water and powerade! :-) June will be cooler. And if temperature is a deciding factor I would chose June.

June may be cooler but it may be only marginally cooler. One year we also froze the first week of June. The next year, same exact week, was unbelievably hot and HUMID. If I had to choice I would go in early June with crossed fingers and legs. It is a dice roll.

Hands down June; more people have the same thing in common in that they can only travel in July and August before the kids go back to school

June it is. We are visiting Rome , Venice and Sorrento.
Thanks everyone