This revised and updated edition of Rudolf Geiger's classic text provides a clear and vivid description of the surface microclimate, its physical basis, and its interactions with the biosphere. The book explains the principles of microclimatology and illustrates how they apply to a wide array of subfields. Those new to the field will find it especially valuable as a guide to understanding and quantifying the vast and ever-increasing literature on the subject. This edition has been revised to keep abreast of current research in all aspects of microclimatology, to provide more examples of work from North America, and to more clearly illustrate how surface energy fluxes are linked to the nature of the surface environment. The authors have added discussions dealing with the speed of sound, the use of vegetative barriers to reduce sound, and physiological control of energy and moisture exchanges. They have also expanded the discussion of microclimatic effects on animal and human behavior and dwellings, as well as updated methods of measurement and notation. Designed as an introductory text for students in environmental science, this book will also be an essential reference for scientists seeking a clear understanding of the nature and physical basis of the climate near the ground, and its interactions with the biosphere.