Estimating and mapping urban heat islands of the UK by interpolation from the UK Met Office observing network

In this paper, we estimate the climatological impact of urbanisation in the UK as derived from the present and historical set of temperature observations from the UK network of meteorological observing stations. A well-established method for interpolation of in-situ temperature observations is used to make an estimate of temperatures at urban weather station locations based on rural climate data. This method avoids reliance on simple pairing of urban–rural stations commonly used for station-based analysis, and explicitly accounts for other topographic features such as elevation and coastal effects that will introduce geographical differences in temperature. The method is then applied to select a network of ‘rural’ weather stations deemed to be largely free from the direct influence of urban micro-climate effects. Comparison of the temperature grids derived from the ‘urban’ and ‘rural only’ station sets enables quantification of climatological urban heat island intensity across the UK and the influence on temperature in the UK national observational network observations from urban stations. Practical application: This new method allows the estimation of the urban heat island for towns and cities of any size. Researchers will find it useful when making predictions of the urban heat island and of climate change in the urban environment, and when investigating morbidity and mortality due to overheating in buildings.