Honestly, on a windy rooftop terrace, weight is your best friend. Lightweight aluminum, thin tubular steel, or hollow resin benches can become dangerous projectiles in a strong gust. You want something dense, low-profile, and weather-resistant. Here are the heavy bench options I would actually consider.
Concrete benches are the easiest recommendation. A typical five to six foot concrete bench weighs anywhere from 250 to 500 pounds, which makes it extremely unlikely to move in even serious wind. They come in modern board-formed finishes, smooth minimal styles, and classic garden looks. Maintenance is basically occasional sealing, and they hold up beautifully outdoors. The trade-off is that they are semi-permanent. You will not want to rearrange them every weekend, and you should double-check that your roof can handle the load, especially if you already have planters or other heavy furniture.
Cast iron and thick steel benches are another strong choice. Many classic cast iron or heavy gauge steel benches weigh between 150 and 300 pounds. They have enough mass to resist most wind, but you need to pay attention to the finish. Look for powder-coated, galvanized, or marine-grade coatings if you get rain, humidity, or salt air. I would also add rubber feet or a weatherproof mat underneath to prevent rust stains and scratches on your terrace floor. In very exposed locations, bolt the legs to the deck substructure or use heavy-duty L-brackets so the bench cannot slide or tip.
Solid hardwood benches, especially teak, ipé, or jarrah, are another good option if you want warmth without sacrificing too much weight. A six-foot solid teak bench can easily weigh 100 to 180 pounds. Dense hardwood is naturally weather-resistant, and teak ages into a nice gray patina without cracking easily in sun and wind. Avoid thin folding frames and lightweight slat construction. Go with thick, solid joinery and chunky legs. If you want extra security, you can discreetly add steel weights under the seat or anchor the bench with galvanized brackets.
Stone and granite benches are the heaviest high-end option. A solid granite bench can weigh 400 to 800 pounds or more, which makes wind basically a non-issue. They are expensive and difficult to move, but they look elegant, permanent, and will last for decades. This is the right call if you want a true focal point and never want to think about wind again.
What I would not choose is anything made from hollow resin, thin aluminum, lightweight wicker, or flimsy tubular steel unless you plan to bolt it down. Even some benches that look heavy can catch wind badly if the back is tall and solid. For a windy rooftop, keep the silhouette low or choose a slatted back. A slatted or low back reduces wind load significantly compared with a high solid panel. Also look for adjustable feet or add rubber shims so the bench sits evenly and does not scrape the deck.
If the terrace is extremely exposed, anchor it. Many concrete and metal benches have pre-drilled holes or can be secured with galvanized brackets. For most rooftops, my personal pick is a six-foot solid teak or powder-coated cast iron bench with a slatted back, placed on rubber pads, plus anchor brackets if you are above ten floors or in a gusty city. If you want zero worry, go concrete or stone.