Florence in late September 2021?

Given the reports that Europe is stumbling out of he gate on the vaccine front, Italy this Sept looks quite unlikely.

I would not pre-pay for anything unless there was a CLEAR refund policy.

My $0.02

I agree with Joe that Sept of this year still looks iffy. At this point, your vaccination is immaterial- it's the current status in Italy, which lags behind your country in its vaccination program. And who knows whether there will be another big spike due to a new variant before the vax programs are completed.

The first thing I do before I plan an international trip is go to https://travel.state.gov/ > International Travel > Country Information > enter Italy in the Learn about your destination field > enter (> means clink on the link). You’ll see that the government has listed Italy as a level 3 which means to reconsider travel due to COVID-19. If you click on the COVID-19 Information link and scroll down, you’ll see the same link again and if you click on it it says:
Last updated: 03/05/2021
*** Effective January 26, all airline passengers to the United States ages two years and older must provide a negative COVID-19 viral test taken within three calendar days of travel. Alternatively, travelers to the U.S. may provide documentation from a licensed health care provider of having recovered from COVID-19 in the 90 days preceding travel. Check the CDC website for additional information and Frequently Asked Questions.
Country-Specific Information:
• Italy has confirmed cases of COVID-19 within its borders.
• The Department of State has issued a Level 3 Travel Advisory for Italy recommending that travelers avoid all nonessential travel to Italy. In addition, the Centers for Disease Control (CDC) has issued a Level 4 Travel Health Notice for Italy due to COVID-19 concerns and similarly recommends that travelers defer all nonessential travel to Italy.
My conclusion is to wait until it drops to a level 2 before you begin your planning. Remember, when you return to the US, you have to provide a negative test result to enter. This sounds like a hassle and something you won't want to do.

Even if it is possible to travel there, the question it's impossible to answer is how much will things on the ground there have returned to normal by September. Or at least to enough of a normal that you can enjoy it fully.

No one knows the answer to that question. It's a guess, and my guess is that September is too soon to hope for a near-normal visit to Florence (or anywhere in Europe).

While I agree that no one knows what the status will be in September...
Some of the above posts imply that Italy's adults need to be fully or close to fully vaccinated before they allow international visitors.
That is also a complete unknown in my eyes, Europe may welcome fully vaccinated North American's well before they are done with their own vaccination program.

Everything is unknown and subject to change right now.

I imagine in the near future providing proof that you are fully vaccinated will become more important than providing a negative test result.

No matter the future, my recommendation if you really want to go is hold off on making any actual bookings for the time being and just mentally plan out the potential trip ; which this forum is best at anyway.
You could book hotels on a major website as long as no prepayment is required and you can fully cancel the reservation without penalty.
I would not book airfare, as you may get your money back or you may get a voucher.
I know I currently posses some vouchers/credits that become worthless if the airline/hotel goes bankrupt ; which unfortunately does happen in this environment so I prefer not to add to my collection of those.

Plus I am kind of tied into using those sources even if I see something better from another provider I prefer.

Some of the above posts imply that Italy's adults need to be fully or close to fully vaccinated before they allow international visitors.
That is also a complete unknown in my eyes, Europe may welcome fully vaccinated North American's well before they are done with their own vaccination program.

If the local population is not vaccinated, I doubt they will be allowed to be out in circulation operating all the businesses that serve tourists. I believe the vaccination program at the destination is critical to it being open for tourists.

It is hard for me to imagine that Europe will not be open to Europe by Sept 2021 (even if not open to US tourists). If you have a legitimate business/educational reason for being in Florence, it would seem that you could be a part of that.

Nothing is certain, of course, so I wouldn't buy that non-refundable airline ticket yet, but I would be checking to see if your research project meets the standard for business or educational travel.

It is important to note that travel between regions in Italy has not been allowed in several months - for Italians. Yes, the vaccine roll out is much slower here but hopefully it will pick up pace otherwise it will take years to vaccinate people (according to the Modena newspaper). Until Italians are able to travel between regions (or at this point TOWNS) I can not see international travelers having that opportunity. I am cautiously optimistic for fall but not holding my breath.

Blockquote

If the local population is not vaccinated, I doubt they will be allowed to be out in circulation operating all the businesses that serve tourists. I believe the vaccination program at the destination is critical to it being open for tourists.

Blockquote

While hard to compare to an island, Madeira (part of Europe) recently announced fully vaccinated tourists are welcome and can skip the otherwise necessary PCR tests.
We are a long way from Sept. but think we will slowly see over the coming months locations that rely on tourism open up to those vaccinated regardless if their own population has been fully vaccinated.

Not suggesting Italy will do this in a month but within 4 months if they are up to 30-40% of their own adults vaccinated including all in higher risk categories ; yeah I can definitely see that happening.

No one is vaccinating children yet, plus not every adult will agree to take a vaccine, so we are a very long way from the entire population anywhere being fully vaccinated in the US or in Europe. The travel industry will not survive if every nation prohibited tourists until that happens.

Any thoughts?

Well, keep things refundable and if Italy is open to tourists in September ......... Have an Amazing Time!!!

To say anything else is just blowing gas (which I am usually very good at).

Here is a depressing article: https://www.bloomberg.com/news/articles/2021-03-10/how-to-think-about-booking-europe-summer-travel-2021-during-covid

I have also been hoping to plan a long (4 month) visit in the Fall....I have been unable to find definitive rules for anyone holding an Italian passport...I am a dual citizen of US/Italy. All the reading I've done only refer to US visitors not able to enter Italy yet. Has anyone seen a reference to Italian citizen but not an "essential" trip? I do not own property or have family but would be able to quarantine if necessary since I want to spend multiple months. Fingers crossed for September 2021!

For what it’s worth: https://www.reuters.com/article/us-health-coronavirus-italy-vaccines-idUSKBN2B50L0

I had to cancel a 3-week trip in Apr/May of last year. I do not plan on rebooking anything in Europe until Spring '22. Now, I may start making reservations this fall, but I do not anticipate traveling any sooner than that. Also, I would strongly suggest getting vaccinated as that may be a prerequisite for travel anywhere outside the US.