If I remember correctly, I do believe we had a discussion about zone information last year.
The problem is that there are so many different variable even within each zone itself. Someone living in Zone 7 in Tennessee is going to have very different growing issues than someone, also in Zone 7 but living on the Atlantic coast in say Virginia (where I am) or Delaware (where I used to be)
To continue........
Which is not to say giving a general idea of where we all are is not helpful to those is very different parts of the country.