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Charts: The water at the tip of Florida is reaching hot tub-level highs

MIAMI, FLORIDA - JULY 11: In an aerial view, a boat arrives at the Haulover inlet from the Atlantic Ocean to on July 11, 2023 in Miami, Florida. The surface ocean temperatures in parts of Florida are 92 to 96 degrees Fahrenheit, the warmer coastal ocean water is threatening Florida's coral reefs, and could create stronger tropical storms and hurricanes. (Photo by Joe Raedle/Getty Images)rJoe Raedle/Getty

Come on in, the water’s fine — if you like hot tubs. The water temperature on the tip of Florida hit 100 degrees two days in a row this week. Experts say that could potentially be the hottest seawater ever measured, although there are some issues with the reading.

The buoy collecting data on water temperature in shallow Manatee Bay, which is off the Everglades and blocked off from the ocean by North Key Largo, recorded a temperature of 100.2 degrees Sunday night and 101.1 degrees Monday evening.

The ocean temperature in a bay off Florida reached over 100 degrees on two days this week. That's hot tub-level.National Data Buoy Center

The Caribbean Sea and southern Gulf of Mexico, including around southern Florida, have been experiencing a marine heat wave for several months. It is expected to last through October, according to the National Oceanic and Atmospheric Administration.


The temperatures around southern Florida are the warmest since records began being kept in 1981, NOAA said earlier this month, noting that the heat waves can “cause stress to corals and other marine ecosystems” and could strengthen hurricanes and other tropical storms that pass through the region.

Just 26 miles away from Manatee Bay, scientists saw devastating effects from prolonged hot water surrounding Florida — devastating coral bleaching and even some death in what had been one of the Florida Keys’ most resilient reefs. Climate change has been fueling record-setting temperatures across the globe this month.

Weather records for sea water temperature are unofficial, and there are certain conditions in this reading that could disqualify it for a top mark, meteorologists said. But National Weather Service meteorologist George Rizzuto said the 100 degree readings could be a record.

In this image provide by NOAA, a turtle swam near coral, some partially white or pink, that are signs of bleaching, at Cheeca Rocks off the coast of Islamorada, Fla., on Sunday, July 23. Andrew Ibarra/Associated Press

“It seems plausible,” Rizzuto said. “That is a potential record.”

A 2020 study listed a 99.7 degree mark in Kuwait Bay in July 2020 as the world’s highest recorded sea surface temperature. Rizzuto said a new record from Florida is plausible because nearby buoys measured in the 98 and 99 degree range.


This image provide by NOAA, shows a dead coral at Cheeca Rocks off the coast of Islamorada, Fla., on July 23.Andrew Ibarra/Associated Press

“This is a hot tub. I like my hot tub around 100, 101. That’s what was recorded yesterday,” said Yale Climate Connections meteorologist Jeff Masters. Hot tub maker Jacuzzi recommends water between 100 and 102 degrees.

“We've never seen a record-breaking event like this before,” Masters said.

In this image provide by NOAA, a fish swam near coral showing signs of bleaching at Cheeca Rocks off the coast of Islamorada, Fla.Andrew Ibarra/Associated Press

But he and University of Miami tropical meteorologist Brian McNoldy said while the hot temperatures fit with what's happening around Florida, it may not be accepted as a record because the area is shallow, has sea grasses in it and may be influenced by warm land in the nearby Everglades National Park.

Still, McNoldy said, “it's amazing.”

The fact that two 100-degree measurements were taken in consecutive days gives credence to the readings, McNoldy said. Water temperatures have been in the upper 90s in the area for more than two weeks.

At one of those nearby buoys, at Middle Key, about three miles to the northeast, temperatures reached about 98 degrees around the same time as the Manatee Bay buoy.

The ocean temperature at Middle Key reached around 98 degrees in recent days.National Data

Here’s a view from a NASA office of the overall warm ocean water in the Gulf of Mexico and Florida from July 6 to today. Note that areas in white are approaching 95 degrees (35 Celsius) and the temperatures are as of early morning.

This animation shows the ocean temperature in the Gulf of Mexico and off Florida in recent days.NASA/SPoRT

There aren’t many coral reefs in Manatee Bay, but elsewhere in the Florida Keys, scientists diving at Cheeca Rocks found bleaching and even death in some of the Keys’ most resilient corals, said Ian Enochs, lead of the coral program at the National Oceanic and Atmospheric Administration Atlantic Oceanographic and Meteorological Laboratory.


NOAA researcher Andrew Ibarra, who took his kayak to the area because of the hot water, said, “I found that the entire reef was bleached out. Every single coral colony was exhibiting some form of paling, partial bleaching or full out bleaching.”

Some coral even had died, he said. This is on top of bleaching seen last week by the University of Miami as NOAA increased the level of alert for coral problems earlier this month.

Until the 1980s coral bleaching was mostly unheard of around the globe yet “now we’ve reached the point where it’s become routine,” Enochs said. Bleaching, which doesn’t kill coral but weakens it and could lead to death, occurs when water temperatures pass the upper 80s, Enochs said.

“This is more, earlier than we have ever seen,” Enochs said. “I’m nervous by how early this is occurring.”

This all comes as sea surface temperatures worldwide have broken monthly records for heat in April, May and June, according to NOAA. And temperatures in the North Atlantic are off the charts — as much as 9 to 11 degrees warmer than normal in some spots near Newfoundland, McNoldy said.

Max Holmes, president and chief executive of the Woodwell Climate Research Center in Woods Hole, said the temperatures, which are coming during a summer of worrisome weather extremes, were “insane, crazy.”


“Everywhere you look the impacts of climate change are hitting us in the face with events that are, on the one hand, surprising but on the other hand exactly what we’ve been predicting and yelling about for years,” he said.

“It’s here in a big way. It’s hard to wrap your head around,” he said. “This needs to be a wakeup call for everybody. We need to stop putting greenhouse gases in the atmosphere. We need to figure out how to pull greenhouse gases out of the atmosphere at scale.”

Martin Finucane can be reached at martin.finucane@globe.com.