When does fall start in south Florida?
Continentally speaking, Labor Day is the tradition.
Celestially speaking, it’s the Autumnal Equinox – September 22nd
But those milestones don’t do much to budge the thermometer south of Okeechobee. Daytime highs still hover around 90º F and nighttime lows in the 70s through September,
In other words, still summer!
Rest assured, south Florida is inexorably spinning towards its “Big Four” fall milestones.
The first is the night-time drop of the mercury below 70. That will happen in early to mid October.
When it does, the south peninsular rain machine shuts down.
The second is the night-time drop of the mercury below 60º F.
That will happen at first by chance, like a gift from the gods, in the form of our first “fall” cold front. It’s a long expected event, met with great euphoria from coast to coast, and usually only short lived (a day or two), but it’s a sign of things to come:
By mid November average daily night-time temperatures consistently drops below the 60º F line,
At least they do in Naples.
(Sorry Miami, you’re average daily night-time lows stay above 60 all year … thanks to the nearby Gulf Stream.)
The third milestone is the "official" end of hurricane season. That happens November 30th,
Right around that time is when we hit the fourth milestone – and “unofficial” finish line – of fall:
Cypress trees finally lose their needles.
That’s as sure a sign as there is that winter is upon us, Florida style.