Recent challenges such as climate change, heat stress, and dwindling water resources have become critical concerns in agriculture. This study aimed to assess the impact of using shade nets on physiological and microclimatic parameters, as well as the quantitative and qualitative yields of four grapevine cultivars. The cultivars Sahebi, Red Sultana, Red Asgari, and Mish Pestan were evaluated for traits such as chlorophyll fluorescence, yield, and microclimate conditions both under and outside a green shading net with 50% porosity. The shading net effectively lowered the temperature by 3.2 ºC while increasing humidity by 5.31%. Regarding chlorophyll stress, the net significantly increased maximum fluorescence and variable fluorescence by 48% and 46.2%, respectively, although it did not significantly affect primary fluorescence or the potential quantum yield. The net also resulted in significant reductions of external canopy temperature (15.9%), leaf
temperature (17.6%), internal canopy temperature (15.2%), and CO2 levels (6.5%). In contrast, canopy humidity rose by 64.3%. Under the shade net, internodal length increased by 66.2%, and vine yields saw an increase of up to 65%. The interaction effect between cultivar and the shading net was significant for internal canopy humidity, temperature, and total soluble solids. The findings demonstrated that using a shading net helped reduce heat stress, improved fruit quality, and delayed ripening. However, for table grape production, it is recommended to remove the shading net at the veraison stage to avoid delayed ripening.