Clothes for Sicily and Rome - late November into December

The website timeanddate.com has actual, day-by-day historical temperatures going back at least ten years. Reviewing several years' worth of November and December statistics will give you an idea of the range of weather you may experience. I've linked to the November 2018 data for Palermo.

A heavy coat will only be good if it's really cold--layering is the answer.
A raincoat, over a sweater, over a long sleeve shirt, over a teeshirt, will get you through a pretty cold situation, and various combinations of those items will work in any other situation.

I like to check the temp/rainfall charts at the bottom of the tour pages for an estimate. Of course, what you are used to where you live makes a difference, too.

What temperatures are you used to? Someone from a very hot climate might feel cold in 50 degree F temps while those of us from the north would walk around without a jacket.

Also if you will be outdoors for long periods (like hiking, not walking a city where you will go into cafes or sights frequently) you will need warmer clothes. Also if you go up to high altitudes (Etna?).

For me, used to Chicago winters, I’d bring jeans or other normal weight pants, long sleeve tops, a couple t shirts, a few sweaters or sweatshirts, and a thinner rain jacket. Medium weight socks and comfortable shoes, not special winter shoes just walking shoes or boots. The sweater can go over the tops if it’s extra cold or either the sweater or the top could be worn alone.

So in theory you could have a long sleeve t shirt, a sweater and a jacket if it’s cold. It’s also conceivable to be warm - average highs in Palermo are 60F and it’s possible it will hit 70F. To me that’s short sleeve shirt weather. So a short sleeve shirt with a sweater or jacket you can remove if it gets warm is another option.

That’s plenty for places where the average low is 40F. That’s overnight, daytime temps are likely to be 50 to 60, quite possibly higher.

Thin gloves and a hat are overkill for even the lows, but do pack small and will keep you warm in clothes that aren’t quite perfect for the temps. This would be good if you hit a cold spell or are hiking.

Avoid cotton --- when it gets damp, it will make you feel colder. A thin, cashmere cardigan is a good layer --- being able to button or unbutton (or zip and unzip) it makes it better for a range of temperatures than a pullover. You probably won't need any sort of winter coat in Rome (although Romans may be wrapped in fur or down), but a wind-breaking jacket of some kind is useful. I take a thin, down-alternative vest because I tend to get cold easily --- a vest is nice because if you have too many layers on your arms you feel constricted or may not be able to get your outermost layer on. A thin, warm scarf is a good idea. Wear your warm layers just to get onto the plane instead of packing them if you are going carry-on only.

We haven't been to Sicily in winter, but pretty much everywhere else in Italy in November and December. Rome won't be as cold as areas that are very humid in winter. But you can always buy more warm clothing (hat, gloves, down vest) if you find that you need to.

I agree with much of the above except the hat and gloves. When my hands and head are warm, I’m warm. A stocking type cap and thin gloves take little room. We were in Rome and Sicily in May and it was cold. Glad I had them and that I packed jeans (which I never do). Mt. Etna was freezing!

Just returned (end of trip 11/6) from Italy with the end of our trip in Rome and Amalfi area. I agree with looking at weather averages, however, bear in mind that these are averages and many types of extremes are possible. Also, I'm guessing it is hard to forecast weather in those areas due to mountains and coastline, because the forecast even a few hours in advance was often wrong. A few days that were forecast rainy and complete cloud cover turned out to have a fair amount of sun and my sunglasses were back at the hotel. Likewise, we got caught in wind/showers when none were forecast. I highly recommend lightweight gloves and a hat tucked into your day bag. I also like layers. I use a rain coat for a top layer with fleece or wool sweaters layered underneath when needed. I also carry a visor at all times. It keeps both the sun and the rain off my face. I love to have both capri and full length leggings. They can be worn with a tunic type top and under dresses/skirts and pants. We had and used rain pants. They were easy for me to pull on over leggings.

Difference between temps during the day/evening seemed to depend most on cloud cover. Clear nights were much chillier. Also wind was at times a big factor.

I just took a second look, and noticed the OP is male. My husband brought 1 pair of jeans, 1 pair of dressier pants (tan chinos) and 2 pair of convertible pants/shorts. He wore the convertible pants most often, they dry fast and obviously have the advantage of becoming shorts/pants when needed. Also my husband has large feet (size 15) so he typically only likes to bring the shoes on his feet, I encouraged him to bring a second pair of light weight sporty shoes. This turned out to be a good choice since his main shoes could be left to dry when need be. He also liked thin wool socks for rainy days (and wished he had a second pair) For myself, I had a couple pairs of quick drying sport socks which turned out to be invaluable.

EDITED TO ADD: for us, rain was a bit of an issue. I had tried to order the waterproof version of Allbirds, called "Mizzles" I believe. People love that brand of sneakers and I was willing to give them a try. Alas, they were completely sold out, and indeed, people seem to love them. November is a rainier time of year, you might take a look and see if they are in stock and might work for you. I did see many men and women wearing Allbirds, and in fact, people that say only tourists wear sneakers are sorely wrong, or at least in Italy, they are.