Hotel recommendations in Florence for September
https://www.7florence.com/en/7florence/
Directly across from the train station if arriving by train and very easy walk to all the sights and good restaurants.
Relais Tosinghi. Dumo is nearly next door. Place is clean, secure and comfortable. 10-15 minutes walk from Santa Maria Novella station.
Personally I like Hotel Globus but its been years since my stay. https://www.hotelglobus.com/?utm_source=google&utm_medium=organic&utm_campaign=GoogleMyBusiness
Check out the Hotel California -- yep, that's the name. Beautiful place and within walking distance of everything.
Take a look at the Hotel Loggiato dei Serviti at https://www.loggiatodeiservitihotel.it. We stayed there back in 2010 based on a Rick Steves guidebook recommendation and really enjoyed it!
We really enjoyed Hotel Albani which is only a couple of blocks from the train station on a quiet side street Via Fiume. It is an easy walk from the hotel to the Duomo, Accademia, Uffizi, and Ponte Vecchio. We had a Superior Double room on an upper floor with a lovely balcony overlooking the rooftops of Florence. When we stayed there the breakfast was excellent.
We are staying at the Hotel Renaissance Firenze in September, it looks to be lovely and located in the historic center.
On a previous RS tour, we stayed in the Hotel California, it has a rooftop terrace which we enjoyed at sunset. It is also close to everything.