that could be true regarding warm climates and hot ladies 
but IMHO the reason for the gorgeous NYC females was/is two-fold
1. NYC has the largest population in the whole us of a... by far
2. there's lots of cash money to be found in manhattan, so therefore the sexy and hot girls go there to try and land some of that cash
Problem with many of the NYC women is that they are "one sided", meaning it's "their side" that only matters. As was many have attitude problems, and act like gods gift to man, but don't realize that they can be replaced real quick. They tend to lack social grace, charm, and "warmth".
Southern, and Cali women have NYC women beat when it comes to the "intagibles".
I would to go to Italy, Spain, Germany, Greece.