微气候是指一个细小范围内与周边环境气候有异的现象。在自然环境中，微气候通常出现于水体旁边，该处的气温会较其周边低。而在不少城市内，大量的建筑物则会做成另一种微气候，气温会较其周边高，这种现象被称为热岛现象。例如在森林中，如果在从中间开一条马路的时候，原本相连的栖地，就会被切割成二半，使得原本相连的栖地被切割，而可能造成其中的微气候的改变，连成其连续气候的中断或者改变，而这种改变可能会造成一些物种的消失，或者增生，尤其在对于一些气候是比较敏感的物种，会因为微气候的改变而消失。

A microclimate is a local set of atmospheric conditions that differ from those of the surrounding area. Because climate is a statistic, which implies spatial and temporal variation of the mean values of the describing parametres, it is clear that within a region could occur and persist in time, sets of statiscally distinct conditions, i. e., microclimates. The term may refer to areas as small as a few square meters or square feet (for example a garden bed) or as large as many square kilometers or square miles.