Hazardous heat engulfs South Florida as Miami issues first May Heat Advisory in 15 years

Miami will see a heat index that could top 107 degrees. This has prompted the National Weather Service in Miami to issue its first Heat Advisory in the month of May in at least 15 years.

MIAMI – An early-season heat wave is baking South Florida with a dangerous combination of heat and humidity through the end of the week. 

The FOX Forecast Center said a front is stalled across the central part of the state, with summer-like heat continuing to build to its south. High temperatures are expected to soar into the 90s, and record-high temperatures will continue to be in jeopardy through Sunday. 


Dew points indicate how much moisture is in the air, and they are forecast to remain in the upper 60s to upper 70s throughout the state through Friday. 

"It's the combo of high heat and humidity that becomes so dangerous," FOX Weather Meteorologist Britta Merwin said. "How do we cool down? We step outside, we sweat, that sweat evaporates, and your internal body temperature will drop in response to that."

Miami will see a heat index that could top 107 degrees. This has prompted the National Weather Service in Miami to issue its first Heat Advisory in the month of May in at least 15 years. 

Nighttime will bring little relief as temperatures stay in the 80s. Temperatures are expected to return to more typical Florida heat early next week.

As of Thursday, Miami has already set six daily record highs for 2024, including last week. 

Florida seeing early-season, record-breaking heat

Several records have been tied or broken across South Florida this week. Key West, for example, was absolutely baking on Wednesday.

The city tied its highest heat index ever at a sweltering 115 degrees. The actual temperature also reached 92 degrees on Wednesday, which broke its old record for that date of 90 degrees back in 1884.

While Key West is the southernmost point in the U.S., numerous records were broken farther north.

Miami reached 96 degrees on Wednesday, which was its second-highest May temperature on record. The highest was 98 degrees in May 2017.

And if you thought nighttime would bring some relief from the heat, think again.

Fort Lauderdale tied its all-time warmest low temperature on record Tuesday when it only dropped to 85 degrees. That tied its old record set back on July 23, 1945.

Key West, too, only dropped to 82 degrees on Tuesday morning, which broke a daily record-warm low of 81 degrees from 1995.

West Palm Beach also saw a record-warm low temperature of 81 degrees on Wednesday morning, breaking its old record of 79 degrees set in 1938.

Check twice before you lock

With the early heat in Florida, parents and guardians must be vigilant in checking their vehicles for children and pets. Even on an 80-degree day, leaving a child or pet inside a car can be deadly. 


When temperatures outside are above 80 degrees, your vehicle becomes a convection oven. Within 20 minutes, temperatures inside a car can rise nearly 30 degrees, causing life-threatening heat stroke for children.

The graphic below shows how hot a car can become with the temperatures forecast this week. 

"We have feels-like temperatures that will be in the triple digits. You got to think about heat safety," Merwin said. "Think about kids in cars, pets in cars, your neighbors. Everybody kind of needs to check in on one another as we take a look at early onset for heat."