The question was raised in the other southern thread:http://boards.straightdope.com/sdmb/showthread.php?p=17752405&posted=1#post17752405
As Zeldar says, the Panhandle is unquestionable Southern. I will add that Boynton Beach and south is solidly not Southern. (I live and work well south of that, in the very Yankee surroundings of Boca Raton and Pompano Beach).
Is it maybe Orlando? I know there’s very rednecky areas in rural West Palm Beach, so maybe even further south than Orlando?
Ocala
This will probably not help matters much:
We were in Florida 13 years and lived in a few different locales–Ocala, then Clearwater/St. Pete, then Vero Beach, then just north of Jacksonville, then Winter Haven. None of the larger towns/cities seemed “southern” but the more rural areas did.
I would say a line from Cedar Key to St. Augustine. Anything below that is not true southern anymore. There are “rednecky areas” in Detroit, so that by itself does not move the demarcation line, it’s just an historical anomaly.
Seconded.
More precisely, I’d say it does a gradual fade, and some places in Sanford can still feel a bit Alabamish. By the time you reach the suburbs of Orlando, (Altamonte Springs/Lake Mary) the vast majority of the people are first or second generation Yankees. South of I-4, you can find some spots in the rural areas (Polk County most definitely being one) that are still mostly southern feeling (kind of like small-town Pennsylvania). Lake Wales had former a Klan Member on city council not long ago.
But if you want a border town, Ocala is as good as any.
Good point. To make a comparison, the urban and suburban area of Northern Virginia that is adjacent to DC is mostly “northern” in culture although located in a traditionally “southern” area. Western Loudoun County and the Winchester area are much more “southern” (farming, dozens of independent fundamentalist churches, gun shops, ostentatious tobacco advertising, etc.) even though they are further north than Fairfax and Alexandria.
The panhandle, east to Duval and Clay County (the Jacksonville area) is southern. It should really be part of south Georgia or Alabama. The Apalachee bay area (south of Tallahassee) is known as the “redneck Riviera”.
St. Augustine is “blend” territory. Nice people, but not overly southern or northern.
From Orlando, south, is moving into Yankee territory. Friends from school who now live in Orlando tell me how many more companies have moved there from up north, so a lot more people from away live there now.
Ocala used to be pretty country, but I hear it’s getting built up as well.
Eastern central FL is kind of a mishmash. The town I grew up in was a small college town with a genteel Southern-ish feel to it, but a lot of people were from up North originally, though no one was from from large northern cities. The areas around that town were very country and somewhat southern. Sugary sweet iced tea that causes immediate diabetes is still a food group around there.
The more country areas are probably still very insular and southern, but I don’t know a lot of farmers or cattle ranchers down there, so I can’t discuss.
By the way, Ginnie Springs is a lovely place to camp. It’s not far from Gainesville.
Lee County is a border zone in that it still has a strong redneck good ol boy network in place but the huge influx of northerners is changing it to a northern culture. And the difference is evident in various sections of the County. Pine Island is still in the grip of the Old Guard agricultural interests while the outer islands are the playgrounds of the wealthy Snowbirds. Suburban Sprawl is pushing the redneck culture further inland as old landowners sell out to developers.
It’s touched on elsewhere, but there’s not a line per se. IMHO, here’s how it breaks down:
Starting at St. Augstine on the Atlantic Coast, start at St. Augustine and draw a line in about 20-30 miles, then take the line south down the rest of the state. Consider this area “outside the South”.
On the Gulf Cost side of the state, do the same but start at New Port Richey and go south until you hit the Everglades. Also, “outside the South”.
Draw a circle around Orlando (but not too big). Try to stay within Orlando, direct bedroom communities, and the greater Disney area. “Outside the South”.
Excepting pockets here and there, the rest of Florida is pretty Southern (as most rural areas tend to be).
Cool post! I suspect the same sort of isolation of “enclaves” of non-Southern culture probably applies in most cities and states in the area still geographically, geologically and historically deemed The South.
There are probably quite a few serious attempts to put borders around The South and Southern United States - Wikipedia is at least one of them. See that Missouri is not on the map, but Delaware is. C’est la vie! 
If you have a source (link, book, whatever) that provides an even better version of what The South means, please identify it or post a link to it.
Problem is any rural area even at the extreme south end of the state is pretty rednecky. Orlando is a modern, diverse, cosmopolitan city, but at one end is Bithlo, the (now slightly gentrified) Worst Place In Florida.
Ocala’s not bad, but any dividing line has to jag downward there to encompass the portion of Gainesville that lies west of I-75. Brown people (like me) don’t go past the Cracker Barrel if they know what’s good for them.
I’m just slightly south of Revtim - I live in Plantation, but work in Fort Lauderdale.
I think there are pockets up and down the state, but the “southern” parts are more common north of Palm Beach.
For instance, I remember going down to Miami-Dade near the Redlands, and found myself in agriculture country, with people riding up and down the street on horseback. (Great place for a photo shoot.)
It’s good to note that if you keep going south, you hit the Keys…and some of the middle and lower keys can be quite southern. Then you hit Key West, and…well…that’s kind of it’s own place. Haven’t been there for a few weeks. Fond memories. But I digress…
Although it doesn’t try to draw a line between “South” and “Not South”, this map of the ten “states” of Florida pretty much sums it up. 
When I lived in the Orlando area, I got the sense that the north-south cultural divide was a fuzzy boundary that ran roughly across the middle of the metro area.
I lived in Ocoee, a middle/upper-middle class western suburb that seemed a lot more Southern, culturally speaking, than areas to the south of the Florida’s Turnpike. The majority of my neighbors were transplants from Southern states, and a very high percentage worked in the skilled trades, as opposed to white collar professions. Ocoee’s neighborhoods felt very polished and planned, but it also had a reputation as being a bit “redneck”, and it couldn’t shake its reputation as a sundown town.
Winter Garden, to the west of Ocoee, was a somewhat rough-around-the-edges working class town that was very Southern. Rolling and static Dale Earnhardt shrines were everywhere in the town after he died. Winter Garden’s business district was dominated by the likes of used car/truck dealers, truck cap and accessory dealers, heavy equipment rental, auto body shops, shed dealers, and so on. WG also had a “methy” reputation.
If I had to draw a Yankee-Dixie boundary through Orlando, at least for the time when I lived there, it would probably look something like this.
Winter Garden is full of liberal newlyweds now.
Anybody remember Orlando pre-Disney?
There was a reason the land was so cheap - the place was a dive. I lived in Gainesville in the mid-70’s - the University kept it from being a compete hick town, despite the large tracts of tiny concrete-block houses (1300 sq ft was large - good for at least 4 bedrooms) with flat roofs and slab construction. No sidewalks, and a gravel (if rich) driveway to the single-car carport.
Yes, the large propane tank was in back.
Yup. It was pretty awful.
I also remember a lot of sinkholes in central FL, so I always giggle and point when a news story comes on about people’s houses falling in. Ditto when I hear about a newcomer flipping out over a 3 ft alligator in the driveway.
And, a lot of what’s been built up with McMansions and McMiniMansions, used to be a swamp. That will flood during a hurricane, as a lot of people found out in 2004.
It is also my experience that there’s an additional inner-outer border at the Intercoastal Waterway. Fernandina Beach isn’t Southern but Yulee sure is.
amen.
Nitpick: Intracoastal Waterway