November.

The primary detractor is the weather - don't expect too many sunny days. November is one of the rainiest months of the year, and combined with short days and cooler temperatures it can make for uncomfortable travelling. Since it's off-season many things will be closed for the winter, though the museums and art galleries will still be open. The upside of course is the relative lack of crowds.
If you're dressed for it (goretex, layers, etc.) it's manageable as long as you know what to expect.

I’ve spent at least 40 Novembers in Italy, the first 27 as a resident, the rest visiting my parents in Florence around Thanksgiving. The weather changes depending on whether you are traveling at the beginning or end of November. The early part is statistically the rainiest time of the year, the latter part is generally drier but cooler to cold depending on location. Daylight is short (dark shortly after 5pm). At the end of the month the foliage of trees is largely gone and the sky is a bit hazy to foggy (looks more like winter). Earlier in the month there is still some colorful foliage on trees.

Either beginning or end is not a bad time to visit, provided you don’t mind rain or cold (by cold I mean low 50s during the day and low 40s at night). Places like the Amalfi Coast or the Tuscan countryside are probably not at their best with that kind of weather. Cities will be equally enjoyable with bad weather with the added advantage of having thinner tourist crowds, a major plus when visiting museums and other tourist sites.

We are retired and could go to Italy any month of the year except May, and we now favor November and December. This year, we had to be in Verona for the end of the opera season in early September and it was way too hot for me. Back to early winter for us from now on!

We've been to Florence, Rome, and Matera in November or December and loved it. Also Venice, Naples and the interior of Campania, Emilia-Romagna, Liguria, Piemonte, and Puglia. We've had many famous places either almost all to ourselves or at least without the crush of tourist crowds.

The nice thing about being in cities and towns is that you can usually duck into a bar or store or eat lunch until the rain passes. We have found a few restaurants closed, but there are plenty more that aren't.

So, yes, it MIGHT rain for a while, and it MIGHT be what some people (but not us) call "cold," but in the summer and early fall it is almost sure to be hot or boiling hot most days and also crowded. There are umbrellas and raincoats and warm layers to cope with wet and cold, but there's not much you can do about summer heat and summer crowds. That's our theory, anyway.

I appreciate the feedback! These are some great, helpful responses. This will be my 3rd trip to Italy and completely agree with post # 3- there's NOTHING you can do when the heat is oppressive. The coldest it will be in Italy isn't all that cold for us and we have recently traveled to Iceland and Scotland in the fall when it was rainy and cold. We loved those trips! The early darkness is another thing I've thought of but is less of a worry in the cities because they are beautiful after dark. We are amateur photographers and love getting those night shots when the lights are on. Venice, although not somewhere we will likely go on this trip, is particularly lovely after dark. I think the biggest negative for me will be the lack of foliage and grey wintery skies - might not be the best for pictures, but what we will gain in terms of less crowds and not dying of heat might make it worth it! I'm also thinking more city - less countryside (which is usually inverse for me). Thanks again for all the great tips!

OP--

Everything you're describing is why we travel to Italy in the off-season. I think any time in November would be delightful. Our first trip abroad, to Rome, Florence and Sicily in mid-October nine years ago...even that was a little too bustling for my tastes. Nice weather though. Then, in both 2015 & 2017, we traveled in late February/early March--just fantastic. Yes, froze my buns off in Paris for a couple days, then down in Sorrento as well, but the lack of crowds and ability to really 'see' these destinations and the locals as they really are, without throngs of tourists messing up the works more than offsets any potentially inclement weather.

Next up--unfortunately not til spring (possibly April) 2021--will be a train trip starting in Munich to Hall in Tirol to Verona to Florence to Rome. Can't wait, but I'll probably change my mind six times before we book tickets!

Jay, thanks for your comments! What did you think of the amalfi area in winter? It's probably the part of the trip I'm most worried about - not the cold so much but I have heard that EVERYTHING closes. As in, it might be hard to find dinner? Can that possibly be true? And also that it could just be grey and rainy the whole time. Your next trip sounds great - we were in Munich last October and absolutely loved it.

Yes, the Amalfi Coast will be mostly closed up in November, but don't let that stop you. Do your homework in advance as to what's open or not. In late February (been there twice at that time), it was totally closed, except for Sorrento, which is where you should base, or Salerno. Sorrento is good to go most all year, most all restaurants are open, reasonably-priced and excellent, except your choice of where to stay cuts about in half, so please book early!

But here's the thing--we had the place to ourselves. Took the SITA bus from Sorrento over to Positano, marveled in its beauty, and fortunately found a place open by the Sponda bus stop, Li Galli Bar. Had a wonderful antipasto al fresco lunch. I ask you--would you like to view one of the most beautiful places on earth by yourselves, or with thousands of your 'closest friends'?

So base in Sorrento, take day trips to Pompei, Naples or the A.C. (Sorrento is technically not on the Amalfi Coast), and come back for a nap then dinner. Enjoy!!

Great comments Jay. I have taken a quick look already and I'm sure we can find a place to stay. It sounds like we will find a restaurant or two open as well. And I totally agree with you about the lack of crowds - I'll trade more restaurant choice for lack of crowds any day! We will definitely visit Pompeii while there and then head on to Matera. I have been in the Amalfi Coast area and seen Pompeii before but my husband has not and neither of us have been to Matera! Really looking forward to this!