The question of whether to cover outdoor furniture during harsh weather is crucial for its longevity. The answer depends heavily on the furniture's construction material.
High-quality all-weather materials like powder-coated aluminum, teak, stainless steel, and certain synthetic resins (HDPE wicker) are designed to withstand significant exposure. They resist rust, rot, and moisture damage. However, even these benefit from covering during prolonged heavy rain or snowstorms to prevent water pooling, accelerated wear, and staining.
For furniture made of wrought iron (without proper coating), standard steel, untreated wood, or fabric cushions, covering is non-negotiable. These materials are highly susceptible to rust, warping, mold, and fabric degradation when left exposed to heavy precipitation.
Best practice: Always cover furniture when possible, especially for long-term exposure. Use breathable, waterproof covers that fit snugly to prevent moisture trapping and wind damage. Store cushions indoors. For "all-weather" pieces, covering extends their life and keeps them cleaner, making it a recommended step for severe conditions despite their inherent durability.