No, outdoor rugs are specifically made to endure all weathers, including rain, snow, sleet and sun, and can be left outside all year round. They're usually woven from dyed polypropylene, which is resistant to water, mould, mildew and UV rays.
Can I put an outdoor rug on concrete?
Yes, an outdoor rug can be safely laid on any concrete surface. Remember to seal the concrete first to prevent any excess dye from staining the ground, and fix it to the floor with flooring tape.