I do not have sufficient technical data to provide a confident answer. However, based on the general properties of marble, it may not be the best material for use in very sunny climates, especially for exterior applications. Marble is a natural stone that can be prone to surface damage from direct sunlight, weathering, and other outdoor elements. This can cause discoloration, fading, and eventually, erosion. Additionally, marble is relatively porous, which means it can absorb moisture and be susceptible to cracking and chipping in freeze-thaw cycles. Therefore, it is recommended to consult with stone experts and architects before choosing marble for exterior applications in very sunny climates.