Where Go Hydrology explores seasonal change

Powerful front
Wind, lightning, rain and cooler air

During the winter in south Florida,

It doesn’t rain, but when it does it pours.

Winter fronts are major weather events in south Florida

And often it also brings along lots of wind at the frontal boundary, plus a squall line of thunderstorms that can dole out as much rain as they do lightning strikes, or maybe a combination of the two. Usually they pass through fast, leaving behind a wake of downed palm fronds and a return of blue sky above. The blue is usually a little deeper and clearer and quite a bit cooler and crisper. Fronts in Florida are most remembered for what they leave behind: a momentary reversal of the water cycle, new puddles of rain water, and a day or three (and sometimes a week) of continental air with daytime highs in the 70s.


Balmy winter (so far)
Unless you go a few hours north

It’s not often that you get …

Summer storm clouds in December.

High and low temperatures in Naples and Gainesville, FL

But for much of December, morning fog gave way to puffy white cumulus clouds that by mid afternoon were showing vertical growth. More than just growth, they were giving us spot showers and then blowing west and causing more rain in Naples at night. Hey, I’m all up for a rain shower — but I like my dry season, too. Here’s to hoping that January has some solid and lasting cold fronts in store. I’m ready with my scarf and hat so bring it on!

Caveat: I’m not saying “Gainesville Cold.” That might be a little too frigid for my taste, although I have a fleece, too, that I can pull out if need be. (See chart above)

temperature check

Ode to the sun
And how just a little bit matters

It wasn’t so much the cold …

As it was the lack of sun.

Comparison of day and night temperatures up and down the east coast

While I enjoyed every minute of my winter solstice stay up in Maryland, and the Piedmont Plateau country to be more specific, it was the lack of sun more than the cold that wore me down. On several hikes, despite it being mid day and not rainy, I simply couldn’t find the sun. The clouds and the fog were that dense. Then came the brisker days when sun was out but it didn’t give much warmth. Or more correctly stated, it gave no warmth at all so long as I was walking away from it, leaving me to wonder why I didn’t wear another layer of clothes. Then came the surprise: On the return trip, the shining sun on my face made all the difference. I actually had to strip down a layer.

I know how it all is: It rises, it falls, it rises again. At some point we take the sun for granted. Don’t! The tiniest of sliver made all the difference up north. We most value the things we lack. Living in the land of Florida sunshine I forgot that. Traveling reminds us of the smallest things.

New Year Reprieve
Resolutions officially on hold

This just in:

The new year is officially canceled.

Animation comparing water and calendar years

Well, actually — canceled is a bad way to phrase it. What I mean is that 2022 is already 8 months old. And when I say 2022, I’m talking the water year, not the calendar year. Most people (so I am told — and this truly horrified me) go by the calendar year. I’m not here to tell you that’s a completely flawed approach, but if you’re a hydrologist or trying to get in touch with the water cycle, May 1st not January 1st marks the start of the new year. The reason? May 1st marks the start of south Florida’s 6-month wet season (May-Oct) followed by its 6-month dry season from November through April. January 1st is pretty insignificant in comparison other than being the start of the third month of the dry season.

Or in other words, forget your resolutions and live it up. South Florida’s true new year is still 4 months away.


Beware of this Holiday Monster

The Abominable Snowman is probably the scariest character …

In TV/Movie Holiday Special history.

During day

As a kid I remember covering my eyes when those scenes came on.

Today, adults and children view Rudolph the Red Nose Reindeer commercial-free, thus dampening the devastating effect of having to “wait it out” (through a string of ads) to find out what would happen after those menacing scenes when “Bumbles” (as Yukon Cornelius knew him) appeared — peering over the snow-capped mountains, leaving giant footprints in the arctic plain and most of all the climactic cave scene.

At night

I‘m not saying I’m still scared,

But I did use a zoom lens for this shot.


Happy Winter Solstice
Days get longer from here

The darkest hour …

Is just before the dawn.

Animated diagram of the winter and summer solstice

And especially if that pre-dawn period occurs on December 20th. Not to worry: Daylight hours start to get longer starting on the 21st. The reason: The earth rotates around the sun on a 23.4° tilt. That’s what gives us earthlings our four seasons, or if you live in south Florida, it’s two (i.e. the south Florida exception). To be technically correct, seasons are celestially-defined. Thus, even though they are subtle, south Florida is part of the Northern Hemisphere club — it has four seasons, too.

As for the increase in daylight hours, just don’t expect it to happen overnight. And just to put the current condition in perspective: today’s paltry supply of sunlight is exactly balanced out by a bounty of sunlit (it’s longest day) on the southern side of the globe. At high noon today, the sun will be shining down directly on the Tropic of Capricorn, but for only one day, before starting its 6-month journey north to the Tropic of Cancer on June 21st.


It’s not the cold
Why daylight hours matter most

People go to great extremes …

To get an extra hour (or two) of sleep.

Comparison of the onset of sunset and sunrise in Naples, Florida (left) and Brussels, Belgium (right)

But what about trying to find extra hour or three of sunlight? Come winter time in northernmost latitudes of the Northeast United States (or in Belgium as shown on the chart above), the only escape from 16 hours of darkness (i.e. that’s 2/3rds of the day) is to travel south to a sunnier place like Naples, Florida. Not that it’s perpetual sunshine, but you will gain 2.5 hours of natural illumination. Compare that to the summer solstice where the opposite occurs: Only 7.5 hours hours separates sunset from sunrise compared to 10.3 hours on Florida’s southern tip.

There’s also a (tiny) bit of a temperature difference, but we won’t get into that. The moral of the story: South Florida is brighter, warmer and less dark than the icy northern climes of the continental US and Europe come winter time.

Or in other words, Happy Winter Solstice! And fear not: the downward trend in daylight hours is about to pivot. Just don’t expect it to happen fast.

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.