Outdoor sculptures, exposed to the elements, undergo significant changes over time due to weathering. Natural forces like rain, wind, temperature fluctuations, and pollution gradually alter their appearance and structural integrity.

Materials such as bronze develop a patina—a greenish layer caused by oxidation—which can either enhance or degrade the artwork depending on the artist's intent. Stone sculptures, like marble or limestone, erode from acid rain and freeze-thaw cycles, leading to surface pitting and loss of detail. Modern materials like steel may rust or corrode, while wood can warp or rot.

UV radiation fades pigments and weakens organic binders in painted sculptures. Biological factors, such as lichen growth, further accelerate deterioration. Preservation efforts, including protective coatings and regular maintenance, help mitigate these effects, but weathering remains an inevitable part of an outdoor sculpture's lifecycle. Understanding these processes allows artists and conservators to create more durable public art.