<p>This study aimed to evaluate the effect of tree shades and artificial structures on controlling ultraviolet waves for the first time in the historical city of Yazd, Iran. In this regard, ultraviolet waves were measured in places exposed to sunlight and in the shadows created by urban buildings, engineering structures, and various tree species using an ultraviolet meter. The results indicated broad-leaved trees provide more potent and appropriate protection against ultraviolet rays than coniferous trees. In addition, natural materials such as wood and reed are more suitable for artificial canopies than fabric. Trees and buildings with higher heights had a more significant effect on reducing exposure to ultraviolet rays. Mulberry trees with a height of seven meters had the highest ultraviolet protection factor (equal to 69), and Eldar pine trees had the lowest (equal to 9) among the green space trees. The ultraviolet protection factor in mixed stands of pine and elm significantly differed from the pure stands and was higher (p &lt; 0.01). Using rows of trees on both sidewalks was more effective than planting on one side (p = 0.013). The results indicated the importance of artificial canopies and tree shadows for protecting citizens and tourists from ultraviolet radiation. In addition, the most protective modes for people were identified, and city managers can use them in the urban design of the historic city of Yazd and as a model for research in other cities worldwide.</p>