The study, published May 18 in the Journal of Engineering for Sustainable Buildings and Cities, measured heat pollution from a 36-MW data center in Mesa, Arizona, and a 169-MW data center complex in the neighboring city of Chandler. The researchers found that the air temperature at these facilities was 4 degrees Fahrenheit (2 degrees Celsius) higher than the air temperature downstream. This heating effect extends up to a third of a mile (half a kilometer) from the perimeter of the data centers.
These findings suggest that data centers may exacerbate the urban heat island effect, which occurs when a city experiences warmer temperatures than surrounding rural areas. This is especially worrisome for cities where extreme heat already poses significant public health risks, like Mesa and Chandler.
“Even if these data centers only contribute an additional 1 degree or 2 degrees of heat island magnitude, it could still have a very significant impact on our lives,” lead author David Seller, director of Arizona State University’s School of Geographic Sciences and Urban Planning, said in a press release.
Measuring and mapping waste heat
According to Sellar, a single data center can generate more waste heat than 40,000 homes. Studies show that many of these facilities use air-cooled condenser arrays to offload server-generated heat, creating plumes of hot air that can be 14 to 25 °F (8 to 14 °C) warmer than surrounding temperatures. The wind can then push that air beyond the perimeter of the facility, increasing its impact.
To measure the impact of ambient warming at the Mesa and Chandler data centers, Sellers and his colleagues fitted high-precision, fast-response air temperature sensors to cars and drove them around and around the facilities, logging their GPS location as they went. Data collection took place from June to October, 2025.
Using multiple vehicles allowed researchers to simultaneously measure temperatures above and below the data centers. When he compared them, he found that the air temperature was on average 1.3 to 1.6 °F (0.7 to 0.9 °C), while individual readings were up to 4 °F (2 °C) higher than the air temperature. Based on the consistent alignment of the temperature signal with the prevailing wind direction across multiple locations, dates, and weather conditions, they attributed a warming effect to the features.
Danger is increasing for cities hit by heat
According to Sellers, an increase of about 1 degree Fahrenheit (less than 1 degree Celsius) in average air temperature may not seem like much, but it is enough to increase air conditioning use throughout an entire neighborhood and create even more heat pollution.
Prior modeling for Phoenix, Arizona, showed that waste heat from residential air conditioning alone raises nighttime temperatures by about 2 °F (1 °C). The study said this creates a feedback loop where data center operations increase the energy burden on surrounding areas.
Furthermore, Sellar believes his team’s findings are a conservative estimate. “As we do more measurements in a variety of atmospheric conditions, I think we’re going to see more significant impacts around data centers,” he said.
Previous research suggests that this may indeed be the case. For example, a separate study that is still awaiting peer review found that data centers can create heat islands that affect neighborhoods within a 6-mile radius, much larger than the radius identified by Sailor and his colleagues.
As the tech industry builds more and more data centers near cities vulnerable to extreme heat, it will be important to understand and mitigate their impact on local temperatures. Voyager’s team plans to collect more comprehensive data over a broader period of time and weather conditions. This will help researchers create an atmospheric model to study measures to reduce heat pollution from data centers.
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