microclimate

A microclimate is the climate of a small or localized area that can differ from the surrounding regional climate. It is shaped by local conditions such as topography, bodies of water, vegetation, soil properties, and human-made surfaces.

Key variables in a microclimate include air temperature, humidity, wind, solar radiation, precipitation, and evaporation. These variables interact through processes such as differential heating and cooling of surfaces, shading by trees or buildings, radiative exchange with the sky, heat storage in soils and paving, wind sheltering, and evapotranspiration from vegetation and moist surfaces.

Common microclimates arise in cities, near coastlines, in valleys, and among forests and hills. Urban canyons can exhibit higher daytime temperatures and slower nighttime cooling due to heat-absorbing materials; shaded forest understories often stay cooler and more humid; coastal zones may experience fog and sea breezes; valleys can experience cold air drainage; rooftops can heat up rapidly.

Measurement and mapping of microclimates use local weather stations, data loggers, targeted field surveys, and remote sensing to delineate conditions at fine scales. Applications include horticulture and agriculture (matching crops to site-specific conditions), urban planning and architecture (designing to enhance comfort and reduce energy use), and conservation and land management.

Microclimate differs from macroclimate in its scale and variability; local features can create substantial deviations from regional climate patterns. Understanding microclimates supports better landscape design, crop success, and climate adaptation at the local level.