That's an excellent and very practical question! From my own experience and research, the answer really depends on the material and quality of the trash can. Modern outdoor bins are specifically designed to combat sun damage, but their performance varies.
High-density polyethylene (HDPE) plastic bins are the most common. The good ones are treated with UV inhibitors during manufacturing, which are mixed right into the plastic resin. This helps prevent the material from becoming brittle and fading for many seasons. You'll often see claims of 5-10 years of UV resistance. Metal cans, like powder-coated steel or aluminum, rely on their finish. A high-quality, thick powder coating acts as a superb shield against UV rays, preventing rust and color loss. Cheaper, thinly painted metals can chip and rust quickly.
The real weakness isn't usually the body, but the lid and moving parts. Thin plastic lids can become brittle and crack first. Look for bins with reinforced lids and UV-protected plastic wheels or hinges.
My verdict? A premium UV-protected plastic or powder-coated metal bin holds up remarkably well. It will fade slightly over many years, but it won't crumble. The budget bin from a discount store might last only a season or two in direct, harsh sun before becoming faded and fragile. For longevity, always check the product specifications for "UV-resistant" or "UV-stabilized" claims—it's worth the investment.