If you’re comparing a metal street bench and a wooden park bench in a rainy climate, the honest answer is: it depends on the exact material, but a good metal bench usually lasts longer on average.
For a typical public or backyard bench, a powder-coated steel or aluminum frame will generally give you 20 to 30 years before serious rust or structural fatigue sets in, assuming it isn’t sitting in standing water or constantly scratched. Cheap painted steel can fail much faster, sometimes in 10 to 15 years, because once the coating chips, rainwater gets in and rust spreads underneath the surface.
A wooden park bench in the same rainy climate is more variable. Softwoods like pine, fir, or generic pressure-treated lumber often last 10 to 15 years before rot, warping, or joint failure becomes a real problem. Dense hardwoods such as teak, ipe, or white oak can last 20 to 25 years or more, but they usually need periodic cleaning, oiling, or sealing to maintain that lifespan.
So a rough rule of thumb is:
- Metal street bench: 20–30 years average
- Wooden park bench: 10–20 years average
- High-end hardwood bench: 20–25+ years
Rain is hardest on wood because moisture feeds rot fungi and causes repeated swelling and shrinking cycles. Metal doesn’t rot, but it corrodes. The key difference is that rust on a well-coated metal bench is usually slower and easier to stop than rot inside a wooden joint. Aluminum is especially strong in rainy climates because it doesn’t rust the way steel does. It may develop surface oxidation, but it rarely eats through the structure. Cast iron is heavy and durable, but it needs paint touch-ups around scratches and joints.
Wood can still make sense if you prefer the natural look. In a wet climate, choose naturally rot-resistant woods like teak, ipe, shorea, white oak, cedar, or redwood. Avoid untreated pine or low-quality veneer benches. Even the best wood bench needs airflow under the legs, stainless or coated fasteners, and a yearly cleaning to remove moss and mildew.
For the longest life in rainy conditions:
- Keep the bench slightly off wet ground or use feet/standoffs.
- Make sure metal frames have drainage holes so water doesn’t pool inside.
- Touch up scratches in powder coating with cold galvanizing spray or paint.
- Wash both materials twice a year to remove leaf debris, moss, and bird droppings.
- Re-seal or oil wood before the rainy season, but don’t seal over damp wood.
Overall, if you want the lowest-maintenance, longest-lasting option in a rainy climate, choose an aluminum or well-powder-coated steel bench with stainless hardware. If you prefer wood, buy a dense hardwood bench and accept that it will need more regular care. In rough numbers, a metal street bench will average around 20–30 years, while a typical wooden park bench will average around 10–20 years in wet conditions.