Orlando – Ah, the time of year when umbrellas become a fashion statement and thunder rumbles like clockwork — welcome to Central Florida’s rainy season.
Picture warm, sticky days punctuated by the soothing pitter-patter of raindrops and occasional flashes of lightning. But when exactly does this season begin?
Well, that’s the million-dollar question. You see, the rainy season doesn’t punch in on the dot like a clock-in machine. It’s more of a gradual takeover, marked by an uptick in those classic Florida showers and thunderstorms. These weather symphonies aren’t just confined to the peninsula; they also throw their own party over the eastern Gulf of Mexico and Atlantic, treating the waters to late-night and morning shows of their own.
So, how do we know when it’s officially rainy season? Meteorologists at the National Weather Service Tampa Bay Area keep a close eye on something called Precipitable Water (PWAT or PW). Think of it as the atmosphere’s moisture budget — how much water it’s carrying in its metaphorical pockets. This moisture, measured in millimeters or inches, gives us a clue about just how rainy things might get. When PW values drop below a certain threshold, typically around 38mm (1.5 inches), you can bet your last rain boot that thunderstorm coverage will be scarce.
Now, let’s talk phases. The rainy season isn’t just a one-note wonder; it has layers. Late May through June kicks things off with a bang, featuring the kind of storms that make you double-check your homeowner’s insurance. Hail, damaging winds, and even waterspouts can happen with these passing storms, along with the obligatory heavy rainfall and plethora of lightning. The hail in the picture below was during the April hail event last spring.
July through early September is when the rainy season kicks it up a notch. Add in the addition of tropical moisture and the daily downpours ensue. Severe thunderstorms with damaging wind gusts and possibly even a tornado are possible as sea breezes collide. The collision causes air from both sea breezes to rise even more creating thunderstorms. Keep in mind peak hurricane season happens the Sept. 10. Tropical waves, storms, and hurricanes are all additional storms to watch for in addition to our typical sea breeze storms.
Typically the downward trend toward the dry season begins late September into October. Of course hurricane season runs through the end of November, so that’s always something to have in mind. There’s also the early-fall cold fronts that can throw a curveball into the mix, too keeping the rainy season around for a bit longer.
During the rainy season, you may hear the term Bermuda High a lot. The reason? Well, this area of high pressure actually changes the location and timing favored for thunderstorm development based on it’s position and strength. So, if you’re ever caught without an umbrella in central Florida during the rainy season, just remember—it’s not rain, it’s ambiance.