Common use of the term microclimate to describe the climate of a vineyard site, hillside, or valley is clearly wrong. The correct term for these is usually mesoclimate, or possibly site climate or topoclimate.
canopy microclimate is that within and immediately surrounding the vine canopy, or green parts of the vine. There are microclimates on or close to the surfaces of individual leaves, grape bunches, or even berries. Microclimates exist at various positions or depths within the soil. All these distinctions are important in understanding vine responses to environment.