Slough datacentre hub leaves town sweltering

Residents in Slough are questioning whether the town’s huge concentration of datacentres is making the local heat feel even worse during the current UK heatwave.

The issue has sharpened after The Guardian reported on June 26 that people living and working near Slough Trading Estate, widely described as Europe’s largest datacentre hub, say conditions around the site have become unbearable in the summer hot spell.

The story adds a local twist to a wider question facing planners and the technology industry: how much heat do datacentres themselves add to the places around them, and how much is simply the result of extreme weather, concrete and industrial development?

A town under pressure

Guardian reporting said Slough hosts an estimated 30 to 40 large datacentres, with operators including Equinix and Digital Realty serving major clients such as Amazon, Google, Oracle and Microsoft.

The concentration of facilities has turned the town into a major infrastructure node, but also into a place where residents are now asking whether the industry is contributing to hotter streets and harder living conditions.

The report cited temperature readings from the area. The closest weather station to the tech park reached 36.7C on Wednesday and 36.5C the day before. A station in central Slough reached 36.2C on Wednesday and 34.7C the day before.

Those figures sit inside a broader heatwave that is affecting the UK and Europe, which makes attribution difficult. The immediate question is not whether the weather is hot, but whether the datacentre cluster is adding a measurable local effect on top of it.

What residents are saying

Local reaction in the Guardian piece was mixed but pointed. Nawaz, the manager of a Chaiiwala outlet, said he thought datacentres accounted for only 10% to 15% of the local heat and that climate change was the main cause.

That view reflects the uncertainty that hangs over the debate. Residents can feel that their environment has changed, but separating the contribution of servers, cooling systems, roads, roofs and the wider heatwave is not straightforward.

The reporting frames the issue as one of public comfort as much as climate policy. For people working and living near the trading estate, the argument is not theoretical: it is about whether local streets, shops and workplaces are becoming harder to use during hot spells.

The science context

The Guardian tied the Slough complaints to a Cambridge-led preprint on what its authors call the data heat island effect. The study, posted on arXiv in March, estimated that AI datacentres can raise nearby land-surface temperatures by an average of 2C globally.

Andrea Marinoni, a Cambridge associate professor and co-author of the paper, said the work is still early-stage. But the paper also estimated that in some places the local increase could reach as much as 9C.

That does not prove Slough is experiencing the same effect at that scale. It does, however, give the local complaints a scientific framework and suggests that the heat footprint of datacentres may be more significant than many communities have assumed.

The research is also relevant because Slough is not a hypothetical case study. It is a dense industrial cluster with a large concentration of active facilities, so the question of local thermal impact is now playing out in a real and highly visible setting.

Policy and planning

The debate is further complicated by the fact that governments are also looking at datacentre heat as a resource.

In November 2023, the UK government announced funding for a London heat network designed to use waste heat from nearby datacentres to warm thousands of homes and commercial space.

That policy direction shows the industry’s thermal output can be seen in two ways at once: as a potential nuisance for nearby residents and as a source of useful energy if it can be captured and redistributed.

For local planners, that creates a difficult balancing act. Datacentres are valuable pieces of digital infrastructure, but their power demand, cooling needs and physical footprint can bring pressure on land use, emissions, transport and neighbourhood comfort.

What comes next

The unanswered question is how much of Slough’s heat can be attributed specifically to datacentres rather than the wider heatwave and the town’s built environment.

The Guardian story did not report a public response from Equinix, Digital Realty or other operators, and it did not indicate any immediate change in planning rules. But the issue is now clearly on the agenda for residents, researchers and local authorities.

Further scrutiny is likely to focus on whether Slough Borough Council or other planning bodies say more about cooling, emissions or future approvals, and whether operators respond to complaints about heat, noise or sustainability.

Another point to watch is the Cambridge preprint itself. If it advances toward peer review, it could become a more influential reference in future arguments about the local effects of AI and datacentre expansion.

For now, Slough is being used as a test case for a broader question: what happens when one of Europe’s densest datacentre clusters sits inside a town already experiencing extreme summer heat?