Urban Climates

About this book

Urban Climates T.R. Oke, G. Mills, A.

Christen, and J.A. Voogt Cambridge University Press, 2017 — 509 pp. Urban Climates stands as the definitive scientific synthesis of the discipline that Tim Oke spent half a century forging.

Published in 2017 by Cambridge University Press, it is the first comprehensive, unified treatment of modern urban climatology — drawing together decades of field measurements, theoretical modelling, and applied research into a single authoritative volume. The four authors, all world-class physical geographers and atmospheric scientists, have produced a work that is simultaneously a rigorous scientific reference and a practical guide for anyone seeking to understand why cities feel, smell, and behave climatically the way they do. The book opens by establishing what, precisely, an urban ecosystem is.

Rather than treating the city as merely a dense collection of buildings, the authors frame it as a highly modified surface that alters almost every component of the atmospheric system — radiation exchanges, energy balances, wind patterns, the hydrological cycle, air chemistry, and the thermal field. A carefully constructed conceptual vocabulary threads through every chapter: spatial scales are distinguished from the regional down to the street-canyon level, and surface classifications allow meaningful comparison across the vast diversity of city types worldwide. The introduction of the Local Climate Zone (LCZ) framework — a systematic way of classifying urban and rural land cover by structure, fabric, and metabolism — gives practitioners a standardized language for characterizing the thermal and dynamic environment of any neighborhood.

Radiation and the surface energy balance form the physical bedrock of the book. The authors explain in detail how the three-dimensional geometry of urban surfaces — the canyons, rooftops, courtyards, and vegetation patches that together make up the urban fabric — modifies the receipt and redistribution of solar and longwave radiation. Trapped longwave emission from canyon walls, reduced sky-view factors, and the low albedo of dark impervious surfaces all contribute to the retention of heat that is the physical signature of the urban heat island (UHI).

The UHI is examined both as a physical phenomenon and as a socioeconomic and health challenge: the authors synthesize decades of observational studies demonstrating that city centres can be several degrees warmer than surrounding rural areas under calm, clear-sky conditions, with consequences for human thermal comfort, energy demand for cooling, nocturnal sleep quality, and excess mortality during heat waves. Airflow and turbulence occupy a central section of the book, reflecting the critical role that wind plays in dispersing heat, moisture, and pollutants through urban environments. The authors trace airflow across multiple scales, from the mesoscale urban boundary layer — the modified atmospheric column that extends kilometres above a city — down to the roughness sublayer and the individual street canyon.

Building geometry, street orientation, tree canopy density, and urban morphology all shape local wind speed, direction, and turbulence intensity. This material has direct relevance to passive cooling design, pedestrian comfort, and the siting of mechanical ventilation intakes. The chapters on moisture, clouds, and precipitation address a less-publicized dimension of urban climate modification.

Urban areas alter the hydrological cycle through increased impervious surface coverage — which accelerates runoff and reduces evaporative cooling — and through the urban heat island's influence on atmospheric instability and convective precipitation. The authors review evidence that cities can modify rainfall patterns both locally and downwind, intensifying convective storms and shifting precipitation seasonality. These findings have significant implications for urban stormwater management, green infrastructure design, and urban flood risk assessment.

Air quality is addressed with comparable depth. The book explains how the same atmospheric conditions that produce the heat island — stable stratification, low wind speeds, reduced turbulent mixing — also promote the accumulation of traffic-generated and industrial pollutants. The photochemical production of ozone, the formation of urban heat-island-enhanced particulate matter, and the dispersion of nitrogen oxides and carbon monoxide are all examined through the lens of atmospheric physics, giving readers the tools to understand air quality not as a stand-alone environmental problem but as an expression of the same energy and mass exchange processes that govern urban temperature and wind.

The book's final chapters turn to application, addressing how scientific understanding of urban climate processes can be harnessed to design more thermally comfortable, energy-efficient, and resilient cities. Climate-sensitive urban design principles — optimizing street canyon aspect ratios, selecting appropriate surface materials and albedos, strategically placing vegetation, and connecting urban spaces to prevailing breezes — are grounded in the physical theory developed in earlier chapters. The authors also situate urban climatology within the wider context of global climate change, examining how rising baseline temperatures will amplify urban heat island intensities and how cities must adapt their form and infrastructure accordingly.

Written for upper-undergraduate and graduate students in climatology, geography, environmental engineering, and urban design, Urban Climates is equally indispensable for climate consultants, urban planners, building energy modellers, and policymakers. With over two hundred figures, comprehensive references, and a rigour that reflects the authors' combined research careers spanning more than a century, it is not merely a textbook but the foundational reference of an entire scientific field. Source: Oke, T.R., Mills, G., Christen, A. and Voogt, J.A. (2017).

Urban Climates. Cambridge University Press. ISBN 978-1-107-42953-6. https://www.cambridge.org/core/books/urban-climates/A02424592E1C7F9B9CD69DAD57A5B50B