Whether it's okay to leave your outdoor furniture outside all winter depends heavily on the material it's made from and your local climate. As a general rule, storing furniture is the safest option for longevity, but with proper preparation, some pieces can weather the cold.
For durable materials like powder-coated aluminum, teak, or all-weather wicker, leaving them outside is often acceptable if they are thoroughly cleaned and protected with high-quality, breathable waterproof covers that are securely fastened. Ensure water cannot pool on flat surfaces.
However, you should always store furniture made of steel (which can rust), cast iron, or lightweight plastics and resins. Cushions, pillows, and fabrics must be stored indoors in a dry place to prevent mold and mildew.
If you choose to leave furniture outside, follow these steps: 1) Clean it thoroughly with a mild soap solution. 2) Allow it to dry completely. 3) Apply protective treatments (like teak oil or metal protectant) if recommended. 4) Use breathable, waterproof covers designed for outdoor use. 5) Elevate furniture off wet ground or pavers to promote airflow.
Ultimately, storing furniture in a garage, shed, or basement provides the best protection against extreme winter conditions, moisture, and UV damage, ensuring your investment looks great for many summers to come.