Welcome to Winter
Where Go Hydrology investigates if Florida ever gets cold
People winter (the verb) in Florida …
To avoid true winter (the noun) up north.
South Florida beckons as a land of perpetual warmth, and eternal green, where you can recreate outside in a bathing suite, and even go swimming placid gulf during the core winter months while everyone else up north is stuck inside staring out at bare branches, snow drifts and leaden skies.
Lost in the shuffle is the plight of the native Floridian. As tourists rejoice in sandals and short-sleeve shirts, year-rounders walk beside them donned in fleeces, scarves and even long pants. Among all the verdant green palms and ample sunshine, the more observant tourists who venture into the interior swamps may be struck by a peculiar site: a forest of trees without any leaves. Not dead at all, the bare branches are just one of many signs of winter in south Florida.
But winter is defined by falling snow, not cypress needles — right? And if south Florida does have a winter, what are the other signs?
Believe it or not, south Florida gets quite a few cold fronts. How cold? And if not snow, what qualifies as a wintery day in a subtropical clime? To answer that question, we go into deep research mode to uncover the meteorological, botanical and cultural clues.
It’s easy to confuse winter …
For summer in south Florida.
Around half the winter rises up to or above 80° F. That qualifies as summer-like weather if you’re from Up North.
This winter only about 40 percent of the days rose above 80° F, markedly down from the previous five winters. But look at the three-year run of cool winters from 2008 to 2010 when only a quarter of the winter days in Naples broke the 80 degree plane. Or the scorching hot winters of the early 70s when the winter mercury mark topped 80 three times as much.
In south Florida we often mistaken winter for summer, but rarely do we get it confused the other way around. (That doesn’t mean you don’t need a sweater in the summer when the air conditioning is too low!)
People winter in Florida, as in the verb.
We call them snow birds.
To them, without a doubt …
Winter the noun does not exist in south Florida.
But for us “year rounders” the thermometer couldn’t be more clear. We go by the 70 degree rule. What is the 70 degree rule? Any day that doesn’t rise above 70° F is winter and any night that doesn’t drop below 70° F is summer. That gives us on average 18 days of winter and 130 days of summer. As for the rest of the days, us “year rounders” call those spring and fall; or in the parlance of the northerners, “– that’s ridiculous, it’s all summer!”
Usually when it comes to Florida rivalries …
It’s Gainesville (UF) versus Tallahassee (FSU).
But when you look at the map,
Gainesville is surprisingly close to the panhandle (i.e. the continent).
A better rivalry in terms of air temperature is to compare Gainesville to further down the south Florida peninsula (i.e. Sunny Naples) as shown above.
By most standards,
Florida doesn’t have a winter.
But starting with Thanksgiving,
The past two months have been reliably cooler.
So yes, we have a winter, just not the polar plunge that New England is dropping into now (i.e. see red line on the chart above).
You know it’s cold in Naples Florida …
When daytime highs don’t rise above 70° F.
Naples gets about 18 of those “frigid cold” days every winter.
Compare that to Fargo, North Dakota where they get +240 such days.
I‘m not here to say which one is colder.
Let’s just agree that each gets winter in its own peculiar way.
As seen in Naples, Florida
Real winter is defined as …
Fargo, North Dakota.
I think the calendar chart above says it all.
Or if you need a more detailed breakdown:
50% of year: daily lows drop below 32° F
25% of year: daily highs stay below 32° F
1 out of 6 days: daily lows drop below 0° F
11 days of year: do not rise above 0° F
In summary, that’s cold!
There’s an old geology saying:
“Here today, gone tomorrow.”
The same can be said for winter in south Florida:
Cold blasts of air never last for more than a day or two before more warm (or mild) air moves in.
Not to mention our metric for measuring winter is very low.
A day that doesn’t rise above 70° F isn’t considered cold up north on the continent.
On average, Naples Florida gets about 18 of those per year.