NEW DELHI, May 19: A new study conducted in the United States has revealed that waste heat generated by large data centres can significantly raise temperatures in nearby downwind neighbourhoods, increasing local heat exposure in already warm urban regions.
The research, carried out in Phoenix, Arizona considered one of the hottest cities in the US found that temperatures in communities located downwind of data centres could rise by as much as 4 degrees Fahrenheit, or nearly 2.2 degrees Celsius.
The study was led by David Sailor, professor and director of the School of Geographical Sciences and Urban Planning at Arizona State University. Researchers said the enormous electricity consumption of modern data centres results in concentrated heat emissions that may worsen urban heat island effects.
According to the research team, the amount of waste heat released by a single large data centre can exceed the heat output generated by nearly 40,000 households in the United States. Scientists explained that air-cooled condenser systems used in these facilities release exhaust air that can be 8 to 14 degrees Celsius warmer than surrounding atmospheric temperatures.
The heated air forms thermal plumes that move into neighbouring residential areas depending on wind direction and weather conditions. Researchers expressed concern that the rapid growth of hyperscale data centres could create serious environmental and public health challenges in densely populated urban zones.
“They’re such a concentrated load of electricity consumption and hence heat emissions that we became concerned about the impact they could have locally and in downwind neighbourhoods,” Sailor said while discussing the findings.
The study, published in the Journal of Engineering for Sustainable Buildings and Cities, is believed to be the first to directly measure real-time air temperature differences around operational data centres rather than relying solely on satellite-based thermal imaging.
To conduct the research, scientists installed high-accuracy temperature sensors on vehicles that travelled around multiple Phoenix-area data centres and surrounding residential communities between June 18 and October 25, 2025. Multiple cars simultaneously recorded temperatures both upwind and downwind to capture precise heat variations.
Researchers examined four facilities ranging from a 36-megawatt single-building data centre in Mesa to a massive 169-megawatt colocation campus in Chandler, Arizona. The selected centres represented modern “hyperscaler” facilities that support thousands of servers and primarily depend on air-based cooling systems.
The findings showed that average temperatures in downwind locations were between 0.7 and 0.9 degrees Celsius warmer than upwind areas. Scientists also detected thermal effects extending as far as 500 metres from the perimeter of some facilities.
Experts warned that even a small increase in urban temperatures can have major consequences in cities already facing extreme summer heat. Higher local temperatures can increase electricity demand as residents rely more heavily on air conditioning systems, creating a cycle that releases additional heat into the environment.
Researchers noted that rising temperatures linked to data centres could also elevate risks related to heat stress, energy consumption and public health, particularly among vulnerable populations such as elderly residents and low-income communities.
The study comes at a time when global demand for artificial intelligence, cloud computing and digital storage is driving rapid expansion of data centre infrastructure worldwide. Environmental analysts said the findings highlight the need for more sustainable cooling technologies and urban planning measures to reduce long-term heat impacts.
Scientists believe future research conducted under different atmospheric conditions may reveal even stronger heat effects around large-scale data facilities.