On the other side of TN we have the famous Ramp Festival in Cosby. What is a Ramp? A very smelly and not too great tasting onion. If you grew up in Cosby they taste marvelous...at least that's their story!
Also, near Pittsburg in Paris,TN,, is the World's Largest Fish Fry!

In Vermilion, OH (right on the shore of Lake Erie) they have the Woolybear Festival in the fall (Oct?).
When we lived there in the 70's and early 80's my kids loved it.
All the local kids would try to find a woolybear (a caterpillar) and race them at the festival. There also is a parade with everyone dressed like woolybears.
And there always was a local (Cleveland) weather man who was the Grand Marshall of the event and he would predict the winter according to the stripes on the caterpillar. Fun.

The zucchini is the most "local" one. Only 4 miles down the road. Nearby we also have Cherry Festival, Artichoke Festival, and of course the granddaddy of them all the Garlic Festival. (that festival has also been on the food network before). I'm not even going to crazy festivals in San Fransisco.

South Pittsburg is about 45 minutes west of Chattanooga, just off I-24, yes, on the line with Alabama

Does anyone know if there's still a Maple Sugar Festival in Elizabethtown, NY? I remember going there once as a kid, and eating pancakes with REAL maple syrup...mmmmmmm!!!

Another good Tennessee festival "Mule Days" in Columbia, TN. It's about 60 miles south of Nashville

Oh yea, can't forget the Moon Pie festival in Bell Buckle, TN. As you can see, Tennesseans love a good festival!!!

I can only think of a few here locally
The Strawberry Festival
The Manatee Festival
Boomtown Days
The Great American Cooter Festival ( cooter is a turtle)

Only in Florida!

SW Ga festivals:

The National Grits Festival - Warwick, Georgia