It's hot in Houston — and according to a new report, there are only three other U.S. cities that are hotter than H-Town. Photo by Scott Halleran/Getty Images

A new report takes the temperature of urban heat islands across the U.S., and Houston lands in the hotter-than-you-know-what category.

The report, released July 14 by the nonprofit news organization Climate Central, ranks Houston the fourth worst place among the country's urban heat islands. Houston sits behind New Orleans, holding down the No. 1 spot, with Newark, New Jersey, at No. 2 and New York City at No. 3.

"Even for a Houstonian, it's easy to think first of flooding or hurricanes when it comes to regional climate impacts, but increases in daytime and nighttime temperatures at the rate we've seen since the 1970s can do as much — if not more — damage," the Nature Conservancy of Texas notes in a July 2020 news release.

Climate Central emphasizes that extreme urban heat is a public health threat. Texas, Arizona, and California accounted for 37 percent of the country's heat-related deaths between 2004 and 2018, according to U.S. Centers for Disease Control and Prevention (CDC) data released in 2020.

According to the Climate Central report, Houston scored so high because of the city's sizeable share of impermeable surfaces, such as asphalt, concrete, stone, and brick. Impermeable surfaces absorb heat and prevent water from penetrating them.

Climate Central describes urban heat islands as big urban locations that are hotter that outlying areas, especially during the summer. Neighborhoods in a highly developed city can experience peak temperatures that are 15 to 20 degrees above nearby places that have more trees and less pavement, the group says.

The nonprofit created an index to evaluate the intensity of urban heat islands and applied it to 159 cities across the U.S., with Houston claiming the No. 4 spot.

"Heat islands are heavily influenced by albedo, which measures whether a surface reflects sunlight or absorbs and retains the sun's heat," Climate Central says. "Other factors include the amount of impermeable surface, lack of greenery and trees, building height, and heat created by human activities."

Results of a one-day study carried out last August support Climate Central's conclusion about Houston.

The study mapped out heat islands across 320 square miles of Houston and Harris County. More than 80 community scientists fanned out to sample temperatures during three one-hour periods last August 7.

The hottest point measured during the heat-mapping day was 103.3 degrees just southwest of the Galleria on Richmond Avenue near Chimney Rock Road. At the same time, volunteers recorded a temperature of 86.2 degrees about 20 miles to the east on Woodforest Boulevard in Channelview. The result: a 17.1-degree temperature swing between Houston and Harris County's hottest and coolest areas at the same point in time.

The Houston Harris Heat Action Team — a collaboration among the Houston Advanced Research Center, the City of Houston, Harris County Public Health, and the Nature Conservancy of Texas — sponsored the heat-mapping exercise with financial support from Lowe's and Shell.

"The data has identified Houston's 'hot spots' and shows that some Houstonians are impacted by urban heat island effect more than others," Houston Mayor Sylvester Turner said in a January news release about the heat-mapping study. "We will work with partners to target our cooling and health strategies … to better help Houstonians beat the heat."

The heat-mapping event was conducted in conjunction with Resilient Houston, the city's campaign to make Houston neighborhoods greener and cooler. The City of Houston says data from the heat-mapping study will help with evaluation of health risks related to extreme heat, coordination of tree plantings, installation of shade-producing structures, establishment of cooling centers, and targeted design of parks, streets, housing, and other infrastructure.

"Science shows that there is real potential to reshape our built environment and cool our cities down where it's needed most," says Suzanne Scott, director of the Nature Conservancy of Texas. "And now, armed with this data, local planners, developers, and environmental groups like ours will be able to leverage smart, cooling urban design strategies that offer multiple benefits — including climate resilience — for all residents, both human and wildlife."

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Houston wearable biosensing company closes $13M pre-IPO round

fresh funding

Wellysis, a Seoul, South Korea-headquartered wearable biosensing company with its U.S. subsidiary based in Houston, has closed a $13.5 million pre-IPO funding round and plans to expand its Texas operations.

The round was led by Korea Investment Partners, Kyobo Life Insurance, Kyobo Securities, Kolon Investment and a co-general partner fund backed by SBI Investment and Samsung Securities, according to a news release.

Wellysis reports that the latest round brings its total capital raised to about $30 million. The company is working toward a Korea Securities Dealers Automated Quotations listing in Q4 2026 or Q1 2027.

Wellysis is known for its continuous ECG/EKG monitor with AI reporting. Its lightweight and waterproof S-Patch cardiac monitor is designed for extended testing periods of up to 14 days on a single battery charge.

The company says that the funding will go toward commercializing the next generation of the S-Patch, known as the S-Patch MX, which will be able to capture more than 30 biometric signals, including ECG, temperature and body composition.

Wellysis also reports that it will use the funding to expand its Houston-based operations, specifically in its commercial, clinical and customer success teams.

Additionally, the company plans to accelerate the product development of two other biometric products:

  • CardioAI, an AI-powered diagnostic software platform designed to support clinical interpretation, workflow efficiency and scalable cardiac analysis
  • BioArmour, a non-medical biometric monitoring solution for the sports, public safety and defense sectors

“This pre-IPO round validates both our technology and our readiness to scale globally,” Young Juhn, CEO of Wellysis, said in the release. “With FDA-cleared solutions, expanding U.S. operations, and a strong AI roadmap, Wellysis is positioned to redefine how cardiac data is captured, interpreted, and acted upon across healthcare systems worldwide.”

Wellysis was founded in 2019 as a spinoff of Samsung. Its S-Patch runs off of a Samsung Smart Health Processor. The company's U.S. subsidiary, Wellysis USA Inc., was established in Houston in 2023 and was a resident of JLABS@TMC.

Elon Musk vows to launch solar-powered data centers in space

To Outer Space

Elon Musk vowed this week to upend another industry just as he did with cars and rockets — and once again he's taking on long odds.

The world's richest man said he wants to put as many as a million satellites into orbit to form vast, solar-powered data centers in space — a move to allow expanded use of artificial intelligence and chatbots without triggering blackouts and sending utility bills soaring.

To finance that effort, Musk combined SpaceX with his AI business on Monday, February 2, and plans a big initial public offering of the combined company.

“Space-based AI is obviously the only way to scale,” Musk wrote on SpaceX’s website, adding about his solar ambitions, “It’s always sunny in space!”

But scientists and industry experts say even Musk — who outsmarted Detroit to turn Tesla into the world’s most valuable automaker — faces formidable technical, financial and environmental obstacles.

Feeling the heat

Capturing the sun’s energy from space to run chatbots and other AI tools would ease pressure on power grids and cut demand for sprawling computing warehouses that are consuming farms and forests and vast amounts of water to cool.

But space presents its own set of problems.

Data centers generate enormous heat. Space seems to offer a solution because it is cold. But it is also a vacuum, trapping heat inside objects in the same way that a Thermos keeps coffee hot using double walls with no air between them.

“An uncooled computer chip in space would overheat and melt much faster than one on Earth,” said Josep Jornet, a computer and electrical engineering professor at Northeastern University.

One fix is to build giant radiator panels that glow in infrared light to push the heat “out into the dark void,” says Jornet, noting that the technology has worked on a small scale, including on the International Space Station. But for Musk's data centers, he says, it would require an array of “massive, fragile structures that have never been built before.”

Floating debris

Then there is space junk.

A single malfunctioning satellite breaking down or losing orbit could trigger a cascade of collisions, potentially disrupting emergency communications, weather forecasting and other services.

Musk noted in a recent regulatory filing that he has had only one “low-velocity debris generating event" in seven years running Starlink, his satellite communications network. Starlink has operated about 10,000 satellites — but that's a fraction of the million or so he now plans to put in space.

“We could reach a tipping point where the chance of collision is going to be too great," said University at Buffalo's John Crassidis, a former NASA engineer. “And these objects are going fast -- 17,500 miles per hour. There could be very violent collisions."

No repair crews

Even without collisions, satellites fail, chips degrade, parts break.

Special GPU graphics chips used by AI companies, for instance, can become damaged and need to be replaced.

“On Earth, what you would do is send someone down to the data center," said Baiju Bhatt, CEO of Aetherflux, a space-based solar energy company. "You replace the server, you replace the GPU, you’d do some surgery on that thing and you’d slide it back in.”

But no such repair crew exists in orbit, and those GPUs in space could get damaged due to their exposure to high-energy particles from the sun.

Bhatt says one workaround is to overprovision the satellite with extra chips to replace the ones that fail. But that’s an expensive proposition given they are likely to cost tens of thousands of dollars each, and current Starlink satellites only have a lifespan of about five years.

Competition — and leverage

Musk is not alone trying to solve these problems.

A company in Redmond, Washington, called Starcloud, launched a satellite in November carrying a single Nvidia-made AI computer chip to test out how it would fare in space. Google is exploring orbital data centers in a venture it calls Project Suncatcher. And Jeff Bezos’ Blue Origin announced plans in January for a constellation of more than 5,000 satellites to start launching late next year, though its focus has been more on communications than AI.

Still, Musk has an edge: He's got rockets.

Starcloud had to use one of his Falcon rockets to put its chip in space last year. Aetherflux plans to send a set of chips it calls a Galactic Brain to space on a SpaceX rocket later this year. And Google may also need to turn to Musk to get its first two planned prototype satellites off the ground by early next year.

Pierre Lionnet, a research director at the trade association Eurospace, says Musk routinely charges rivals far more than he charges himself —- as much as $20,000 per kilo of payload versus $2,000 internally.

He said Musk’s announcements this week signal that he plans to use that advantage to win this new space race.

“When he says we are going to put these data centers in space, it’s a way of telling the others we will keep these low launch costs for myself,” said Lionnet. “It’s a kind of powerplay.”

Johnson Space Center and UT partner to expand research, workforce development

onward and upward

NASA’s Johnson Space Center in Houston has forged a partnership with the University of Texas System to expand collaboration on research, workforce development and education that supports space exploration and national security.

“It’s an exciting time for the UT System and NASA to come together in new ways because Texas is at the epicenter of America’s space future. It’s an area where America is dominant, and we are committed as a university system to maintaining and growing that dominance,” Dr. John Zerwas, chancellor of the UT System, said in a news release.

Vanessa Wyche, director of Johnson Space Center, added that the partnership with the UT System “will enable us to meet our nation’s exploration goals and advance the future of space exploration.”

The news release noted that UT Health Houston and the UT Medical Branch in Galveston already collaborate with NASA. The UT Medical Branch’s aerospace medicine residency program and UT Health Houston’s space medicine program train NASA astronauts.

“We’re living through a unique moment where aerospace innovation, national security, economic transformation, and scientific discovery are converging like never before in Texas," Zerwas said. “UT institutions are uniquely positioned to partner with NASA in building a stronger and safer Texas.”

Zerwas became chancellor of the UT System in 2025. He joined the system in 2019 as executive vice chancellor for health affairs. Zerwas represented northwestern Ford Bend County in the Texas House from 2007 to 2019.

In 1996, he co-founded a Houston-area medical practice that became part of US Anesthesia Partners in 2012. He remained active in the practice until joining the UT System. Zerwas was chief medical officer of the Memorial Hermann Hospital System from 2003 to 2008 and was its chief physician integration officer until 2009.

Zerwas, a 1973 graduate of the Houston area’s Bellaire High School, is an alumnus of the University of Houston and Baylor College of Medicine.