No hot tub needed in South Florida this week. Water temperatures in the bays between the mainland and the Florida Keys were so warm Monday that meteorologists say they were among the hottest ocean temperatures ever recorded on Earth.

Water temperature at a buoy in Manatee Bay south of Miami reached an incredible 101.1 degrees Monday evening.

That could be a new world record, besting an unofficial 99.7 degree temperature once reported in Kuwait. But meteorologists say the Florida gauge’s location in dark water near land could make that difficult to determine.

Heat has been building in South Florida for weeks as the region and much of the western United States sweltered under much warmer than normal temperatures.

The heat index – what the temperature feels like – in Miami has topped 100 degrees in the city for 43 consecutive days, 11 days longer than the previous record, Brian McNoldy, a senior research associate at the Rosenstiel School of Marine, Atmospheric and Earth Science at the University of Miami, tweeted on Monday.

“Calling this heatwave unprecedented is an understatement,” McNoldy said.

What to know about that hot sea surface temperature

Was Monday’s 101.1 degree temperature in Manatee Bay a valid record measurement?

That depends on the surrounding circumstances, said Jeff Masters, a meteorologist for Yale Climate Connections. The reading would need to be verified, and no one keeps official sea surface temperature records, Masters said.

The potential, unofficial record sea surface temperature is 99.7 degrees in the middle of Kuwait Bay in the northwestern Persian Gulf, Masters said. That’s according to a 2020 study by scientists with the Environmental and Life Science Research Center at the Kuwait Institute for Scientific Research. 

The Manatee Bay gauge is very close to land, south of Biscayne Bay, and measures the water temperature at a depth of 5 feet.