The microclimate of a surface consists of a relatively thin boundary layer covering the surface, and the airspace above it that is influenced - to a lesser extent - by the surface. Temperature, wind velocity, and often humidity and radiation change more with height in this fluctuating airspace than in higher air layers. A microclimate is usually assumed to extend to a height at which 99 percent of the prevailing local conditions of temperature and wind velocity are reached. This height is determined largely by the relative strength of local air turbulence.
Climate research also includes the study of very small-scale climatic regions, an area of investigation known as microclimatology. A microclimate is one that extends from a particular kind of surface - for example, a lawn, a pond, a parking lot - to a height at which this climate begins to blend with the general climatic conditions of a given locality. Microclimates are, in fact, the aerial environments in which individual plants and animals live. A landscape is a complex mosaic of many such climates - from urban street canyons or small vegetation canopies on down to the atmosphere surrounding the bodies of individual organisms. These climates, although influenced by larger-scale regional conditions, are essentially created by the energy "budget" of the local surface where the given microclimate occurs.