The possible record comes amid growing concerns around the effects of the climate crisis, as scientists say the planet is reaching a tipping point with more frequent extreme weather events.
Weather records for seawater temperature are unofficial. But the initial reading on a buoy at Manatee Bay near the Florida Keys – an archipelago off the state’s southern coast – hit 38.4C (101.1F) on Monday evening, said National Weather Service meteorologist George Rizzuto.
On Sunday night, the water temperature reached 37.9C (100.2F) at the same location.
“It seems plausible,” Rizzuto told The Associated Press news agency. “That is a potential record.”
The previous potential record was recorded in a 2020 study that listed water temperature in Kuwait Bay in July of that year at 37.6C (99.7F).
“This is a hot tub. I like my hot tub around 100, 101 [37.8, 38.3 Celsius]. That’s what was recorded yesterday,” Yale Climate Connections meteorologist Jeff Masters told the AP.
“We’ve never seen a record-breaking event like this before.”
The temperatures recorded around Florida are the latest worrying sign of the effects of climate change on the world’s oceans.
Earlier this week, scientists warned that an ocean stream that circulates water south to north in the Atlantic Ocean could collapse as early as 2025.
The collapse of the current, known as the Atlantic Meridional Overturning Circulation (AMOC), could cause devastating effects across the world, including raising sea levels and causing more frequent storms.
A study by researchers at the University of Copenhagen said the stream could stop between 2025 and 2095. The researchers cautioned that their findings “should call for fast and effective measures to reduce global greenhouse gas emissions” to prevent that from happening.
Peter de Menocal, an oceanographer and paleoclimatologist, said the ocean circulation is vital to the global climate system and its consistency across geographic areas.
“A shift in this current or a shutdown in this current puts all of those expectations into uncertainty,” he told Al Jazeera.
For his part, Matthew England, an oceanographer at the University of New South Wales in Sydney, Australia, called for urgent action to tackle the climate crisis.
“It is not too late because every single fraction of a degree – every 10th of a degree we push the planet’s temperatures up – stacks up higher and higher odds of these disruptive changes to our climate system,” England told Al Jazeera.
Threatening ecosystems
Meanwhile, the United Nations’ World Meteorological Organization (WMO) also said earlier this month that global sea temperatures have reached monthly record highs since May.
The WMO and the National Oceanic and Atmospheric Administration (NOAA) have said temperatures like those in South Florida can be deadly for marine life and threaten ocean ecosystems.
That can also impact human food supplies and livelihoods for those whose work is tied to the water.
As he worked his knife to filet fish hauled into Key Largo, in the upper Florida Keys, on Tuesday, fishing boat captain Dustin Hansel said the catch has been getting “slower and slower” for the past five summers.
He also said he had been seeing more dead fish in waters in the area. “As far as all of our bay waters, any near-shore waters, everything is super, super hot,” Hansel told the Reuters news agency.
NOAA warned this month that the warmer water around Florida could supercharge tropical storms and hurricanes, which build more energy over warmer waters. Rising temperatures are also severely stressing coral reefs, the agency said.