UK data centres warned over climate resilience gap

Krystal has warned that UK data centres are not adequately prepared for climate change, arguing that heat resilience is receiving too little scrutiny as demand for AI infrastructure grows.

The hosting provider says higher temperatures, flooding and strain on the electricity network could undermine facilities that support digital services across healthcare, finance, public services and business. Industry debate, it argues, has focused heavily on whether the grid can supply enough electricity for AI workloads, while paying less attention to whether buildings and cooling systems can keep operating through more frequent periods of extreme weather.

The warning follows several high-profile disruptions. The Dawn supercomputer at the University of Cambridge was taken offline for nine days during an extended period of high temperatures. Earlier incidents also affected data centre operations in London, including shutdowns linked to cooling failures during 40C heat and IT outages at Guy's and St Thomas' NHS Foundation Trust that disrupted access to patient records.

Krystal argues these incidents should be seen as signs of a broader infrastructure problem rather than isolated failures. Although data centres are now classed as part of the UK's Critical National Infrastructure, adaptation policy has not kept pace with that status.

Policy gap

The company pointed to the Climate Change Committee's report on national adaptation, which identifies hospitals, schools and care homes as priorities for heat resilience but gives little attention to data centres. As a result, operators are largely left to set their own resilience standards until the next stage of national adaptation policy is developed.

The argument comes as pressure on UK data centres increases. Britain has set a target of 6GW of AI-capable data centre capacity by 2030, while the connection queue for new electricity projects has grown beyond 125GW. For operators, that creates a twin challenge: securing power and ensuring facilities can function safely as temperatures rise.

According to Krystal, many existing sites were designed around assumptions of a more moderate British climate. As a result, cooling systems in older facilities may have less headroom than operators need during prolonged heatwaves.

The company cited analysis from techUK that identifies heatwaves, temperature variability, water scarcity, flooding and power grid strain as key climate risks for UK data centres. It also pointed to Met Office data showing that the number of days exceeding 28C has doubled in recent years, while days reaching 30C or higher have trebled.

Cooling pressure

Data centres generate heat constantly because servers run around the clock. Operators rely on cooling equipment to maintain safe temperatures, but hotter ambient conditions reduce efficiency and can force systems to depend more heavily on mechanical cooling.

Krystal said the problem is not limited to temperatures inside facilities. High outdoor temperatures can also reduce the amount of electricity overhead lines can carry safely, just as demand rises because cooling systems are working harder. If grid constraints coincide with cooling failures, the risk of an outage rises sharply.

Flooding presents another threat. Some UK data centres are located in areas exposed to flooding or are served by ageing drainage systems, raising the risk that water ingress could disable power, cooling equipment and hardware at the same time.

Newer facilities are being designed with higher temperature tolerances, free-cooling approaches and renewable energy sources in mind. Even so, much of the UK's installed data centre base predates the recent run of unusually hot summers, making upgrades a pressing issue for operators seeking to reduce the risk of disruption.

Retrofitting challenge

Krystal said retrofitting is possible but requires significant investment and a realistic assessment of weaknesses in existing facilities. It highlighted several measures operators are using to improve resilience, including larger cooling reserves, real-time environmental monitoring, stronger backup arrangements for renewable energy supply and stress testing based on extreme scenarios rather than historic averages.

The company also argued that businesses using third-party hosting should examine where their data is physically stored, what flood and heat risks apply to the site, how uptime guarantees are supported, what energy sources are used and whether providers disclose past incidents openly.

Dave Kimberley, Chief Executive Officer of Krystal, said the current approach to service guarantees can conceal the impact of climate risk on data centre performance.

"The majority, if not everybody, in this industry can quote you an uptime percentage to at least two decimal places. But if you ask what temperature range that number caters to, some won't be as vocal. That's where the real gap is. Resilience is so often reported as an average, but in a drastically changing climate, averages lose their meaning.

A data centre doesn't fail on a bad month. It fails on a single extreme day. Until 'built for extremes' is the standard data centres are actually built to, businesses are inheriting climate risk without even knowing they've taken it on.

We spend a lot of time talking about whether the grid can power the AI boom. Nobody is asking the equally urgent question of whether the buildings themselves will still be standing, thermally, by the time that power arrives. Retrofitting for climate is no longer optional. It is already overdue."