The 9th International Conference on Urban Climate V. Masson a, ⁎, A. Lemonsu a , J. Voogt b,c a National Centre for Meteorological Research, METEO-FRANCE/CNRS, Toulouse, France b University of Western Ontario, London, Canada c International Association for Urban Climate, Dublin, Ireland article info abstract Article history: Received 10 March 2017 Received in revised form 12 July 2017 Accepted 17 July 2017 The study of urban climates now represents a full scientific field on its own. The 9th International Conference on Urban Climate (ICUC-9), held in July 2015 in Toulouse, France, provided a recent forum for urban cli- mate scientists to share the results of their research. This introduction paper presents the 20 articles of this special issue. They are representative of the variety of the themes that are encompassed by the urban climate community: study of urban climate processes, new observational and modeling techniques and methods, urban design with climate, geospatial datasets, bioclimatology and health, interdisciplinarity, climate change mitigation & impacts in urban environments, and transfer of urban climate knowledge to urban planners. These papers were selected from student awards winners as well as from more senior researcher contribu- tions. ICUC-9 was the largest ICUC held to date, reflecting the increased in- terest in climate and meteorology at the urban scale by the research community. The selection of articles helps point towards areas of future urban climate research. More planners, social scientists and scientists from outside the ‘pure’ discipline of urban climate were present than dur- ing previous editions, allowing the rise of new themes as interdisciplinary and transfer to urban planners. © 2017 Elsevier B.V. All rights reserved. Keywords: Urban climate Conference Special issue Introduction 1. The conference The study of urban climates now represents a full scientific field on its own. The growth in urbanization worldwide has induced many societal and scientific questions related to the impact of cities and human set- tlements on the atmosphere, at various temporal and spatial scales. From its early beginnings in the 1960s, when the first observations of urban meteorological processes appeared and the study of urban climates Urban Climate 23 (2018) 1–7 ⁎ Corresponding author. E-mail address: valery.masson@meteo.fr (V. Masson). http://dx.doi.org/10.1016/j.uclim.2017.07.007 Contents lists available at ScienceDirect Urban Climate journal homepage: http://www.elsevier.com/locate/uclim 2212-0955/© 2017 Elsevier B.V. All rights reserved.