temperature check

Sweltering December?
And why some call it perfect weather

December is touching up …

At record highs in Florida.

High, low and average air temperatures in Naples and Gainesville, Florida

The reason? Well, it’s south Florida of course. It never gets cold. Or not wintery cold like it does up on the continent. But even by Florida standards, the start of this December has been incredibly warm. Just how balmy has it been? Answer: Warm enough to convince me that we’re still on the summer shoulder season, i.e. mid October or late April. The only salvation: The temperature in my pool and in the gulf is cooler thanks to the thermal stability of water and its ability to hold on to the November temperature plunge. The evenings and morning have been delightfully pleasant, combined after a run with a plunge in the pool. And just to be clear: I’m not complaining, but for someone who grew up in the Northeast, the weather isn’t jiving with what I would normally expect on this calendar date.

But you know what they say about the weather: It’s sort of a corollary on the greenness of the grass, but with a twist: If you don’t like it just stay put, it’s sure to change in 15 minutes (plus or minus a week).

P.S. Deep polar cold front, wherever you are, I’m very unprepared but will welcome you with open arms when you arrive.


Florida’s 70° Rule
For measuring summer and winter

People winter in Florida, as in the verb.

We call them snow birds.

Naples enjoys 3 weeks of winter to 20 weeks of summer

To them, without a doubt …

Winter the noun does not exist in south Florida.

Major caveat: To us “year rounders” the thermometer couldn’t be more clear. We go by the 70 degree rule. What is the 70 degree rule? You know it’s a cold day in Florida when the daytime high doesn’t rise above 70° F. We call those day “winter.” On the other side of the coin, you know its a hot day in Florida when the nighttime low doesn’t drop below 70° F. Going by the 70 degree rule, Naples averages 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!” Well, not if you’re a Florida weather connoisseur.

wet season

Holiday rain guide
Why months don't matter

Often we think of summer rainfall …

In terms of a total or by months.

Summer rainfall in south Florida (inches) replacing months with major holidays as the major color-coded intervals

But maybe a better way to frame it is by major holidays. The reason? For one, the rains that come “just before” and “just after” the official wet season (i.e. as defined from June through October) are just as important as the summer rain itself. Timely spring rains can boost the water table just before the summer rain machine turns on in the same way that November Soakers can prolong the summer high water stand. Look no further than last year’s Eta (in November) as proof. I’m not saying to do away with months (yet), but I do believe holidays for nice mile markers for refining our Water Cycle IQ. BTW: The above chart is for south-Florida wide.

wet season

Rainy or wet season?
Why one is the convention and the other is right

Florida has two seasons, not four:

A summer wet season and a winter dry season.

wet and dry
Summer wet (left) and winter dry (right) seasons

I know what you’re thinking: What happened to fall and spring. It’s a sad story in Florida, but they actually got lost. They somehow slipped away in a tide and, although we’re not a hundred percent sure, we think they are swirling around in a gyre in the mid Atlantic or possibly even washed up on the European shoreline, possibly in Belgium or France.

Joking aside, Florida also has its four celestial seasons. It’s just meteorologically we split the year in two: a six-month wet season from May to October and a six-month dry season from November to April. During the wet season, it rains almost every day, and usually in the form of afternoon thunderstorms. During the dry season, it still rains, but only periodically. Most days are sunny and cloudless, or less clouds. Technically, if you want to split water drops, the wet season doesn’t crank up to high gear until the later part of May and with the exception of tropical events, usually shuts down in early October. But for bookkeeping purposes, we lump May and October into the wet season.

wet and dry
Diagram depicting end of the wet season

Now here’s the tricky part: The term “wet” refers to the regular rains falling from the sky, not the sogginess factor of the water on the ground. Out in the Everglades and Big Cypress Swamp, the ground remains flooded with water for weeks (even months) after the “wet season” has ended.

For me, the term summer “rainy” season — not wet season — is a more accurate description of the season. However, climactically speaking, the term “wet and dry season” climate is the norm. So who am I to argue with the text books?

Final note: The Big Cypress Swamp on average receives around 42 inches of its 53 inch annual rainfall total during the 6-month wet season, or about 80 percent.

Wet or rainy, you get the point.

wet season

Go to Wet Season

dry season

Summer sputters to end
Who keeps turning on and off the switch?

It’s a long summer in south Florida …

And then suddenly like a flip of a switch the rains stop.

The regular pattern of afternoon rains stops in early October

At least that’s how it seemed a week ago.

The late September slug of air had us convinced the summer rain machine had shut down for the year. Ten days later more humid air has returned, and the rain machine has even shown some signs of life. But the bigger picture is it’s starting to sputter off. Usually by Columbus Day (early-mid October), the winter dry season has begun even if from a monthly book-keeping sense we wait until November 1st to start the official dry season clock.


Change in the air?
Not scarf weather, but definitely fall-ish

Although not an official cold front …

And it’s still possible to overheat in the midday sun:

The cooler morning and evening temperatures are a welcome relief. Daytime highs and still ramping up into the high 80s and nighttime lows are staying above 70, but with daylight hours on the wane and last week’s dose of a drier air front, its as cool an early October as I can remember.

Fall is definitely in the air.

Did summer just end?
Just when it was getting interesting

It was shaping up to be a subpar summer …

And then September kicked into high gear.

The swamp finally peaks, but for how long?

Back to back weeks pushed the swamp to its annual peak.

Then came the recent front of dry air?

Overnight the rain machine shut down.

Or is there still time for it to rev back up?

A flooded marl prairie with periphyton

I‘m never one to complain about the start of fall, but seriously – summer was finally starting to get interesting. It’s good to see the swamp’s sheet of water spreading out.