National Statistical

Every year we at ONS publish our UK natural capital accounts. These include an economic value of the benefits that the UK’s natural resources provide to people in the UK, which would otherwise risk not being factored into decision-making. Here, Oliver Mann looks at how we have improved our measurement of ‘urban heat regulation’ – the role that nature plays in cooling our built-up areas.

Our previous data and methods only allowed us to measure urban heat regulation in eleven city regions. We’ve expanded our coverage this year and can now provide valuations for built-up areas across Great Britain. Although most of the accounts have data up only for 2023, we estimate the total annual value of the service was £486 million in 2024.

So what is “urban heat regulating”?

This refers to the capacity of green and blue spaces – for example parks and lakes – to cool our urban environments on hot days. This is an increasing issue, as the average number of hot days in the UK (those with 28 degrees Celsius or above) has nearly doubled over the latest ten years (2015 to 2024) compared with the previous ten years (2005 to 2014). Essentially, we are measuring the economic costs – from reduced productivity caused by heat or expenditure on air conditioning – that are avoided by cooling provided by nature.

This value of this service, one of 16 provided by nature we currently measure, will of course vary from one year to another as the number of hot days fluctuates. So, because in 2023 there were more hot days than in 2024, the total value of urban heat regulating was higher, at £1,016 million. This value for any given area will depend on both the annual number of hot days there and its economic output, as areas with more economic production get higher cost savings through reduced productivity losses.

Typically, London gets larger benefits from urban heat regulating than other parts of Great Britain, both because the number of hot days tends to be higher in the south, and because of the relatively larger local economies in London compared with those elsewhere. Not surprisingly, therefore, the top five areas which get the most value from urban heat regulating are in London – Westminster, followed by Hillingdon, the City of London, Hounslow and Camden – while the lowest values are seen in West Devon in England, followed by Na h-Eileanan Siar (the Western Isles), the Orkney Islands and the Shetland Islands in Scotland, and then the Isle of Anglesey in Wales.

To help users explore these data, and see how their own area compares with others, today we have published a series of interactive maps and charts highlighting differences between local areas in the bulletin, including a map showing the number of hot days and the annual value of urban heat regulating by local authority area, and a graph showing a time series of this from 1998 to 2024 for every local authority.

 Next steps and wider work

We have been developing our natural capital accounts since 2012 and are developing them further. We will also be using the accounts to look at how to measure the depletion of natural resources, which will be needed for calculating Net Domestic Product in line with the internationally agreed System of National Accounts 2025. The accounts also feature in our Inclusive income and wealth accounts, alongside unpaid household labour and more, which are due to be updated on 23 December 2025.

Our work also informs other parts of government – for example, today, the Department for Environment, Food and Rural Affairs will publish the latest edition of its Nature at work for people and the economy, which draws out ten broader policy relevant lessons from our latest Accounts.

Oliver Mann is a senior statistician in the macroeconomic and environment statistics and analysis team at the ONS.