Urban forests play a critical role in improving the quality of life in cities, but in arid environments, little is known about the potential benefits and growth conditions of different tree species. Our study aimed to fill this gap by investigating the relationships between tree dimensions, above-ground biomass carbon storage, and shading potential in three common urban trees in the arid city of Jericho, Palestine, (i.e., Ficus nitida, Delonix regia, and Phoenix dactylifera). The trees were chosen according to their distribution in urban locations and tree vitality, with ages ranging from 20 to 90 years. Based on the results from tree structure measurements, the carbon storage and shading potential were calculated using the City Tree model. The results indicate a moderate to strong relationship between tree height, crown diameter, and crown volume for F. nitida and D. regia (R2 = 0.28–0.66), but no relationship for P. dactylifera (R2 = 0.03–0.06). The findings suggest that the analyzed tree species can considerably contribute to the potential benefits of trees in improving the climate of an arid city: D. regia shows a higher median of above-ground biomass carbon storage of 155 kg C tree−1, while P. dactylifera 91 kg C and F. nitida 76 Kg C. D. regia and F. nitida have a higher median of shading potential, (31 m2–41 m2), respectively. Information on the ecosystem services from urban trees and their relationships in terms of species, age, and tree planting urban location are very important for city planners, in relation to sustainable urban green spaces in arid cities.