Your neighborhood may be getting warmer, and your internet connection could be a contributing factor.

A new study from Arizona State University is the first to directly measure air temperatures both upwind and downwind of data centers in real time, and what researchers found warrants attention from city planners. Heat discharged by data centers is raising air temperatures in surrounding neighborhoods by an average of 1.3 to 1.6 degrees Fahrenheit — and in some cases, by as much as 4 degrees Fahrenheit. The effect was detectable up to a third of a mile, roughly five city blocks, from the facilities’ perimeters.

The findings have been published in the Journal of Engineering for Sustainable Buildings and Cities.

How they measured it

The research team, lead author David Sailor, director of ASU’s School of Geographical Sciences and Urban Planning, along with co-authors Soroush Samareh Abolhassani and Eli Martin, mounted high-accuracy, fast-response temperature sensors on vehicles and drove them around Phoenix-area data centers and surrounding neighborhoods between June 18 and October 25, 2025. Using multiple cars allowed simultaneous upwind and downwind readings.

The four facilities studied ranged from a 36-megawatt single-building data center in Mesa to a 169-megawatt co-location campus in Chandler, reflecting the typical design of hyperscale facilities that house thousands of servers and rely primarily on air-based cooling.

The mechanics of the problem

Data centers are concentrated heat sources. The waste heat produced by a single facility can exceed the combined output of 40,000 households. Air-cooled condenser arrays — the systems that keep servers from overheating — discharge air running 14 to 25 degrees Fahrenheit above the surrounding ambient temperature, producing thermal plumes that drift into neighboring areas.

The downstream effects compound quickly. A 1-degree rise in air temperature is enough to drive increased air conditioning use across entire neighborhoods, and those air conditioners push additional heat back into the surrounding environment.

With US data center capacity projected to more than double by 2030, the cumulative effect on urban temperatures in cities with large concentrations of facilities could be significant. “Even if these data centers only contribute to an additional heat island magnitude of 1 degree or 2 degrees, that can still have a very significant impact on our lives,” Sailor said — particularly in regions where extreme heat already poses public health risks.

What comes next

The researchers are not calling for data centers to be shut down or relocated. Their goal is to work with data center operators and city stakeholders to reduce the thermal footprint without compromising operations. Potential measures include design modifications informed by microclimate modeling, greenbelts or parks to buffer heat discharge, and city-level permitting requirements that account for local heat impact, according to the press release.

A broader data collection effort is planned to capture readings across a wider range of weather conditions, which will feed into an atmospheric model for studying mitigation options.

“Data centers are inherently an important part of our society,” Sailor said, “and they’re going to become even more necessary going forward.”