Again...I was there in August...
I saw NO "thick smog" in any of the ports (as a matter of fact, the only time I ever remember "thick smog" was in Milan in DECEMBER!!
Yes, it is the "hottest month" in the Mediterranean...but, remember also, in Mediterranean climates, there is very little humidity and no rain...So, "hot" there is far more bearable than "hot" in, say, Florida or the Caribbean...Being from Southern California (a Mediterranean climate), the weather was absolutely fine by me--just like home...
As to Europeans on vacation and things closed, the Mediterranean IS where the Europeans go on vacation...All of the "things" tourists want and look for were OPEN and thriving...You don't close your restaurants and gift shops and art galleries and tourist attractions during the high tourist season...
A lot of folks advisiong everyone to avoid August have probably never cruised the region in August...
We found it, yes, a little hot, but, otherwise, absolutely delightful...
I'd go EVERY August if I could...
Sure, given the opportunity, I'd go May or June as well...but absolutely nothing wrong with August...