A numerical simulation study was conducted to reveal the effects of built form on the canopy layer microclimate at the scale of city blocks and to evaluate the role of vegetation in modifying these environments. The study took four metropolitan urban block typologies from Budapest as models and compared their microclimate dynamics with and without vegetation. Microclimate modeling was performed by ENVI-met (Bruse 2011), while MATLAB was utilized for the data analysis. The findings indicate that built form and vegetation are key factors governing the canopy layer microclimate. Their influence is primarily exerted through shading and enclosure.