Hi Lynne,
are considering going to Rome, Florence with possible side trips in early November.
November will be transitioning into the 'low season.' It will slow down some since coming off the summer months and early Autumn.
According to some stats, it appears November may get more rain days compared to early - mid December. I went in early December. The weather was pretty perfect - days were sunny, brisk, and windy, but not annoying. At nightfall, the temps dipped to around the 30's.
My second trip to Rome, same time of year, was very different weather wise. It was above normal temps - a day or two got up to 70 degrees. It rained a bit and got muggy. At night, it got cool and fairly normal. Not freezing.
Airfares and hotels "may" still be charging the higher rates in November. Although, you may be able to catch an airfare deal with airlines who advertise flash sales. That is how I got a super deal on British Airways from Logan to Heathrow (LHR) to Rome (FCO.) (twice)
Museums and other major attractions will have less wait times and less crowding compared to the peak months. A lot of the attractions are within a short walking distance from each other (with the exception of The Vatican, St. Peter's Basilica, and Castel Sant'Angelo - good to group these visits in the same day since they are a little pebble's throw from each other.)
- Oops, forgot about the Colosseum. That is a little further out.
I know you asked about November. For me, both trips to Rome, I loved going in early December - low, RT airfare, low hotel rate.
I found it to be very beautiful for a lot of reasons - seeing The Nativity (sculpted with sand from Venezia), going (many times) to St. Peter's Basilica and leaving with unbelievable and awe-inspiring memories.
Rome begins to sparkle with the start of Christmas decorations - usually on or about December 8th. It is the official start to the Christmas season.
Also, December 8th is the Feast of The Immaculate Conception, where Pope Francis makes his way to Piazza di Spagna to "lay" a laurel wreath at the column of the Immaculate Conception. It is fascinating to witness. He starts off at St. Peter's and hops in his Pope mobile and makes his way to The Spanish Steps.
Last year, they brought back the "Christmas market" at Piazza Navona. It was a big hit. Lots of fun.
In December, you'll experience the popping of the Chestnuts as you walk by the little "almost forgotten" side streets; the street musicians, the Piazzas all lit up once it hits dusk.
Hands down, my most favorite - St. Peter's Basilica. I went different times on a few days and each was an experience in itself. One night, as I walked away from the Basilica, I turned around for one last look - there it was - all lit up in its glory and beauty - just "there" - the statues standing guard http://stpetersbasilica.info/Exterior/Facade/Facade.htm
I "snapped a memory" and finally walked to leave the Piazza.
There was also the huge, huge Christmas Tree. Every year, they have special ornaments and their representation.
You may know already, Florence is a two-hour fast train ride from Rome Termini Station - that is, if your base will be in Rome. You can also go to Orvieto - a sweet, "hill town" that is one hour by regular train from Termini. It is in the Umbria region, but you can get a slice of a "Tuscany feel." It was a little secret, but a lot of travelers have caught on to its quaintness, its relaxing stance, lots of cute shops and proud people.
I could go on and on about Rome in December. Love it! Have fun whenever you go.