Blogging Weather

South Florida’s Rainy Season

The #WeatherNerd in me wants me to write about the upcoming South Florida Rainy Season, so I shall.

For many years up until several years ago the start of the rainy season for each individual year was determined a couple of weeks after it got started. The loose definition of the rainy season are – increased nocturnal showers off the ocean, daily thunderstorms forming at midday where the Gulf and Atlantic sea breezes collide, early-morning temperatures not dropping below 72°F, and dewpoints constantly in the 70s. That daily pattern can start as early as late-April – and as late as early-June. The median start of our rainy season is right around May 15TH, and so several years ago the National Weather Service decided to discontinue the dynamic sliding start date of our rainy season and identify May 15TH as the static fixed start date of our rainy season – no matter the actual conditions at the time.

We generally receive about 70% of our annual rainfall in about 5 months – from May 15TH to October 15TH (the static fixed end date of our rainy season). It generally works out to about 4 to 5 feet of rain (48 to 60 inches / 120 to 150 centimeters). Some rainy seasons are wetter than that. Some drier. Last year some parts of South Florida received nearly 110 inches of rain (280 centimeters) for the entire year !

There are actually “mini seasons” within our 5-month rainy season. June is generally our wettest month of the year. Then it gets somewhat drier in July. (July is also our hottest month.) August and September are wetter with the arrival of the peak of our hurricane season. Then it starts drying-off again in October as our rainy season comes to a gradual close and continental cold fronts begin approaching and moving through from the north.

We actually get cold fronts coming close and coming through well into May and sometimes even into June. The cold fronts this late in the year stall near or directly over us and then eventually dissipate. It’s the old decaying cold fronts that usually kickoff our rainy season each May. Speaking of which – we have a cold front headed this way that should stall out directly over us tomorrow and into the weekend.

We’re still a couple of weeks away from the start of our rainy season for this year, and I’m actually looking forward to it. My car is dirty.

All rights reserved (c) 2021 Christopher M. Day, CountUp Ministries