A systematic review of urban heat island and heat waves research (1991–2022)

Urban Heat Island (UHI) and Heat Waves (HWs) are very important research topics as they have a strong impact on society and their synergies are not enough understood. Urbanisation and global warming are dynamic processes that amplify the UHI intensity and the HWs, as well as their synergies. In this context, it is not a surprise to see that the number of publications tackling the linkages between UHI and HWs has constantly increased in the last decades. The development of new instruments and technologies allowed for consistent improvements in the temporal and spatial resolution of the data that boosted both the monitoring and analysis of the UHI-HW. The use of satellite remote sensing was very limited at the beginning of the analysed period and has become common practice in the last decade. Last, but not least, the interdisciplinary approaches, including physical, social, and economic aspects are more frequent and support the integrated development of the urban areas. Such changes are captured in this review including more than 400 titles, covering the period 1991–2022, aiming to foster further research on emergent climate change risks at urban scales and contextualise the future urban planning. This review provides a comprehensive, accessible and structured overview of the UHI-HW topic as a support for a better understanding of the gaps to be addressed by future research.