The second edition is totally revised and updated. It includes a discussion of climatic change and the importance of the tropics in climatic models, an analysis of the influence of elevation and ocean currents on diurnal and annual ranges of temperature, with new maps of Africa and South America. It includes the Walker circulation and ENSO and their worldwide climate effects. Chapter eight has more details of rainfall distribution in some areas for which sources became available and chapter ten has more emphasis on the relations between tropical climates and agricultural production.