Short answer: yes, you can often leave urban outdoor furniture outside year-round in a city with freezing winters, but I wouldn’t treat it as a leave-it-and-forget-it decision. Outdoor furniture is built to handle weather, but freezing winters bring more than cold: snow load, ice, freeze-thaw cycles, road salt, wind, and long damp spells. Those things can wear down even solid pieces, especially in a city where salt spray and snow-clearing grit end up on balconies, patios, and sidewalks.
The key is the material. Powder-coated aluminum, stainless steel, and good-quality teak or cedar usually handle winter well if they’re maintained. Cheap mild steel, untreated wood, thin resin wicker, and glass tabletops are more likely to rust, crack, warp, or become brittle. If your furniture is lightweight, it can also blow over on a rooftop or balcony, so anchor it or move it to a sheltered spot.
For most people, the practical routine is simple: clean and dry everything before the first hard freeze, bring cushions and textiles indoors, elevate legs off wet pavement, and use a breathable cover rather than a sealed plastic tarp. Plastic can trap moisture and create condensation, which is often worse than leaving the piece exposed to airflow. Remove heavy snow when it’s safe, avoid scraping ice with metal tools, and rinse off road salt when the thaw comes.
If you mean public or commercial street furniture, check the manufacturer’s winter rating; those pieces are usually more robust, but moving parts and finishes still need inspection. If you have storage space, storing delicate pieces is the safest bet, but well-made furniture can usually stay out with a little care. So yes—leave it outside if it’s designed for it, but protect it like you expect winter to be hard on it.