Here's the Spin
For safe operation, ceiling fans used outdoors require waterproof or water-resistant shielding around wiring and other electrical components. Stainless steel hardware prevents rust and special plastics keep fan blades from warping in humidity and heat.
Outdoor blades are given an ultraviolet-resistant coating to prevent fading in sunlight and must withstand wind, salt air and temperature extremes depending on where they are located. Outdoor fans typically generate a higher amount of airflow than indoor units.
This allows them to repel small flying insects and ensures that you feel the breeze they create, even in an open outdoor setting.