For 23 years, a science station on Virginia Key tied to the University of Miami's Rosenstiel School of Marine and Atmospheric Science has carefully tracked conditions in Biscayne Bay. Brian McNoldy, a senior research associate at the school, has never seen anything like the data coming in since September.
Biscayne Bay is hot. Crazy hot. In a field where sustained temperature variations of even one degree can mean big changes, the water off Virginia Key has tracked from five to an astounding 11 degrees above normal in recent months.
And for now, McNoldy doesn't have a sound theory why it's happening.
"I wish I did have a great idea," McNoldy says. "Those are really big numbers we're seeing in relation to the normal temperatures for this time of year."
He's fairly sure of one thing, though: The data isn't the result of bad sensors or weird conditions off Miami's coastline. Similar stations up the Atlantic Coast from Miami to Charleston have also recorded incredibly high water temperatures in recent months. "There are other stations in Georgia and Florida running very well above average," McNoldy says.
Larger trends could be playing into the results. Data shows that overall, 2016 was the hottest year on scientific record. Miami has also had an unusually warm winter, with no temperatures recorded below 50 degrees for just the third time in history.
But those facts don't explain such a big leap in Biscayne Bay's temperatures. In the Atlantic Ocean as a whole, some warmer-than-normal temps have been recorded, but "nothing crazy jumps out," McNoldy says.
It's worth noting that even though temps are way above normal, Biscayne Bay certainly gets hotter in the summer than it has been since September; the water can cook at up to 92 degrees in July and August, McNoldy says. It's just that the bay is normally much cooler over the winter than it has been this year.
If you like this story, consider signing up for our email newsletters.
SHOW ME HOW
You have successfully signed up for your selected newsletter(s) - please keep an eye on your mailbox, we're movin' in!
McNoldy is an atmospheric scientist, not an ecologist, so he doesn't know what sort of effect the bizarrely hot water might have on wildlife. "I'd guess it would have some impact on migration patterns, because animals tend to be very in tune with climate changes for migrations," he says.
For now, he'll continue collecting data. The water has cooled this week with the cold front that's moved over South Florida, but the long-term trend of Biscayne Bay's temperature bears monitoring in these odd climate times.
McNoldy recently finished crunching all the data from January and it showed water "was still in the 5-6°F ballpark above average," he says; the 90-day running mean, which plots through mid-December is an eye-popping 7.2°F above average.