Honestly, the answer depends almost entirely on what the bench is made of and how it’s been treated. I’ve seen wooden benches crack and warp after a single harsh summer, while some metal and plastic ones look nearly new after five years outdoors.
Let’s start with wood. Teak and cedar are naturally oily and dense, so they handle rain and sun better than pine or oak. But even teak will turn silvery gray and develop small surface checks over time. If the bench has a marine-grade varnish or an oil-based sealer, you’ll get more protection, but you’ll need to reapply it every year or two. Untreated softwood is a bad idea for heavy rain — it soaks up moisture, swells, and then cracks when the sun bakes it dry. In short, a quality hardwood bench with regular maintenance can last 20 years or more. A cheap pine bench might start falling apart in three.
Metal benches are a mixed bag. Powder-coated steel or aluminum holds up very well against rain and UV rays, especially if the coating is thick and applied evenly. The weak points are joints, welds, and any spot where the coating gets scratched — that’s where rust starts. Stainless steel is the most weatherproof option but also the most expensive. Wrought iron looks classic but needs repainting every few years to avoid rust bloom. If you live near the coast, salt in the rain makes everything corrode faster, so I’d go with aluminum or high-grade stainless.
Recycled plastic and composite benches are honestly the toughest for heavy rain and strong sun. They don’t absorb water, they don’t rot, and the color is molded all the way through, so UV fading is minimal. A good HDPE bench can sit outside for a decade with zero maintenance. The only downside is that cheap plastic can get brittle over time, especially in freezing winters after a hot summer.
Concrete and stone benches are nearly indestructible in rain and sun. They won’t rust or rot, and the only real issue is surface staining or minor spalling if water gets into tiny cracks and freezes. But they’re heavy, hard to move, and not very comfortable without a cushion.
So my practical advice: if you want a truly durable park bench for heavy rain and constant sun exposure, look for powder-coated aluminum, stainless steel, recycled plastic, or high-quality teak with a good sealer. Check for drainage holes in the seat so water doesn’t pool. And remember — even the best bench will last longer if you wipe off standing water after big storms and cover it or store it during the worst months. No material is completely immune, but some come surprisingly close.