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 startup funding surpasses $1B in 2025 despite national slowdown

by the numbers

Houston-area startups raised more than $1 billion in venture capital during the first half of 2025 — almost double the haul for the first half of last year.

According to the new PitchBook-NCVA Venture Monitor, Houston-area startups raised $417.2 million in the second quarter of this year, compared with $281 million during the same period last year. In the first quarter of 2025, local startups collected $607.5 million in venture capital, compared with $281 million during the same period a year earlier.

Based on those figures, Houston-area startups picked up slightly over $1 billion in VC during the first half of this year, compared with $535 million in the first half of 2024.

Nationally, startups gained almost $70 billion in VC in the second quarter, down 25 percent from the same period a year ago, the PitchBook-NCVA Venture Monitor says.

Nizar Tarhuni, executive vice president of research and market intelligence at PitchBook, explained that “the VC landscape continues to navigate a fragile recovery” and is constrained by economic uncertainty.

However, startups in certain sectors are poised to attract a great deal of attention and venture capital over the next several years, according to the report.

“Companies operating in AI, national security, defense tech, fintech, and crypto — sectors aligned with the administration’s priorities — are attracting disproportionately more investor interest, and this trend will likely continue throughout President Donald Trump’s term,” the report says.

The AI sector accounted for 64 percent of VC deal value in the first half of 2025, according to the report.

Houston space companies land $150M NASA contract for vehicles and robots

space simulations

Houston-based MacLean Engineering and Applied Technology Services LLC, known as METECS, has received a five-year contract from NASA to develop simulations and software services for space-based vehicles and robots, with a maximum value of $150 million.

Two other Houston-area companies, Tietronix Software Inc. and Vedo Systems LLC, were assigned as subcontractors for the award.

"This award is a strong testament to NASA’s continued trust in the quality of our work and their confidence in our ongoing support of the human spaceflight program," John MacLean, president of METECS said in a release.

According to NASA, the awardees are tasked with providing:

  • Simulation and software services for space-based vehicle models and robotic manipulator systems
  • Human biomechanical representations for analysis and development of countermeasure devices
  • Guidance, navigation, and control of space-based vehicles for all flight phases
  • Space-based vehicle on-board computer systems simulations of flight software systems
  • Astronomical object surface interaction simulation of space-based vehicles
  • Graphics support for simulation visualization and engineering analysis
  • Ground-based and onboarding systems to support human-in-the-loop training

The contract is called Simulations and Advanced Software Services II (SASS II), and begins in October. This is the second time METECS has received the SASS award. The first also ran for five years and launched in 2020, according to USASpending.gov.

METECS specializes in simulation, software, robotics and systems analysis. It has previously supported NASA programs, including Orion, EHP, HLS, Lunar Gateway and Artemis. It also serves the energy, agriculture, education and construction sectors.

Tietronix Software has won numerous awards from NASA. Most recently, it won the NASA JSC Exceptional Software Award (2017). Some of its other customers include Houston Independent School District, Baylor College of Medicine, DARPA and Houston Methodist.

Video Systems offers software for implementing human-rated, AI and autonomous systems, as well as engineering services to address the needs of spaceflight and defense. The company has previously worked with NASA and METECS, as well as Axiom Space and defense contractor Lockheed Martin.

The three companies are headquartered near NASA’s Johnson Space Center in Houston.