As record-breaking heat grips South Florida, Miami’s new heat sensors initiative is well underway, capturing how rising temperatures are experienced inside homes and neighborhoods most vulnerable to a changing climate.
The project — funded through the C40 Cool Cities Network’s Heat, Health, and Equity Challenge Fund — began recruiting residents in June, installed sensors in July, and will continue recording temperatures through October. Led by the city’s Office of Resilience and Sustainability (ORS), along with The Miami Foundation and other community-based organizations (CBOs), the effort seeks to close a long-standing “data gap.”
The devices track real-time indoor and outdoor temperature and humidity in roughly 70 households across seven “climate justice” neighborhoods: Overtown, Liberty City, Little Haiti, Allapattah, Little Havana, Flagami and the Little Bahamas.
Camilo Mejia, Catalyst Miami’s director of policy and advocacy, said the initiative goes beyond data collection.
“This is participatory research,” he said. “Without community participation, it's hard to come up with policies and programs that actually address the issues that community members are facing.”
Sensors inside and out
Catalyst Miami is leading the effort in Overtown, overseeing 12 households. Each has three sensors: one located inside by the A/C unit, another placed outside in a protective container to protect it from rain, and a third functioning as a router connected to the household’s internet.
“In real time, we're able to monitor the temperature, the humidity, those types of things on the inside and on the outside, and that information is sent all the way to the city of Miami,” said Nicole Crooks, Catalyst’s community engagement manager.
Through a GIS-based map, the city will be able to document temperature disparities and energy burdens — critical data in a city where over 70% of residents rent and more than 84% stay in the same home year after year.
Residents said installation was easy, and Catalyst checks in monthly to ensure sensors are working properly. Each household also receives a $200 stipend.
“The compensation wasn't the motivation,” said Overtown resident Tania Diaz. “The motivation was that maybe through this, we can find better ways to accommodate the Miami population during heat season.”
For fellow participant Eric Bason, the stipend signaled recognition.
“I try to volunteer for anything that they can get information that's gonna help improve people's lives,” Bason said. “The residents here are experts. That's why you're contacting them for their expertise.”
Everyday heat realities
Miami has already faced a series of heat advisories this summer, with “feels-like” temperatures climbing around 110°F on multiple days in July and August. Last year, the county broke a record with 60 days over a 105°F heat index. In May 2024, two days hit a record-breaking 112°F. In areas like Overtown, heat is even more intense due to lower tree canopy and dense construction, often registering half a degree Celsius hotter than the city average.
For residents like Bason, the difference is clearly felt.
“I have noticed that it's hotter; the heat seems more intense to me,” he said. “Years ago, even if it was hot, I would still walk. It was just the natural heat. It didn't bother me at all. Now I won’t go out until 6 p.m.”
Bason lives in a new senior housing building that has central air conditioning, which keeps the interior comfortable even during heat waves. When the systems break, management provides portable units until repairs are completed.
“They know the severity of the heat. They know that people cannot be in these apartments with this level of heat.”
Diaz, who lives in the same building, said the A/C going out has already made this summer a test of endurance.
“Right before school started, my air conditioner went off,” she recalled. “The management in the building has portable air conditioners, but within three hours, I was sick. Very unpleasant, very uncomfortable. I thought I was gonna pass out. We can’t live without air conditioning in Miami.”
Equity, bills and health
Not all buildings have reliable cooling.
“When you have central air, you're not gonna be as hot. But now if you put these units in your window, to me, that's another story,” Bason said. “I would hope that they [the study] would use a certain percentage in the older buildings and older window units.”
Christopher Rice, who lives in an older building with a window A/C, struggles to keep cool.
“I'm in a one-bedroom,” Rice said. “I have an A/C unit. These A/Cs are not really doing the thing. The living room and the kitchen are fine, but the bedroom is the one that's a little warm, so you don't — I don't really rest at night, and I have to get a fan, and then I really can't take the fan because it hurts my bones.”
Crooks noted how recruiting was limited by a digital divide, acknowledging that without a reliable internet connection, residents couldn’t participate.
“A lot of the families that I have found have the limitations of the window air units and are often families that are struggling and are really significantly impacted by the digital divide,” she said. “As it stands right now, this study is not able to gather their information.”
Rising utility bills compound the strain. Crooks has previously said that seniors oftentimes face difficult choices between food or lights, toilet paper or air conditioning.
“It's very important to make sure that we are staying aware of the realities that are impacting all of our families as it relates to heat,” she said. “With the increased heat, the way in which increases in the FPL bills are really impacting families, and the fact that (Florida’s Low-Income Home Energy Assistance Program) is not an alternative for people who really struggle with being able to pay their electricity bills, it just turns into this cycle.”
Rice feels the cost directly.
“My bills do go up because I have to constantly burn my A/C,” he said. “It's hard when you're living on a fixed income and then you have your light bill running you almost to $200 a month, and then you have other bills to pay off.”
Energy bills will increase further in the coming years as Florida Power & Light plans to raise rates, according to its latest proposal. On the Florida peninsula, monthly rates will climb next year by $3.79.
Extreme heat is already Miami-Dade's deadliest weather hazard, causing an estimated 600 excess deaths a year. Between 2018 and 2022, Florida recorded more than 26,000 ER visits and 5,000 hospitalizations from heat-related illness.
“Respiratory-wise, it's really strenuous to breathe,” Diaz said.
Rice agreed: “The heat makes everything uncomfortable for me. It makes me tired, and sometimes I experience mood swings. I can't handle the heat, period.”
Mejia emphasized that cumulative exposure is the real risk and said that it’s about finding solutions for the whole year, not just summertime.
“If you cannot afford the A/C, if you live in a building that traps heat, it could be hotter inside than the outside, and that type of extreme heat exposure can have severe impacts on people's health and lead to respiratory issues, cardiovascular issues, liver issues, and depression.”
What's next
Sensors will remain installed until October, after which data will be analyzed and shared with residents before informing policy recommendations.
Mejia said Catalyst Miami plans to reconvene participants.
“We intend to meet again with community residents to discuss some of the findings and how those findings can make their way into actual change to address extreme heat.”
For residents, follow-through is key.
“You could study all you want, but if you're not moving on after the study, it means absolutely nothing to me,” said Bason.
This story was produced by The Miami Times, one of the oldest Black-owned newspapers in the country, as part of a content sharing partnership with the WLRN newsroom. Read more at miamitimesonline.com.
