Short answer: mostly yes, but not completely. A domed top is a smart design choice for an urban trash can because it sheds rainwater instead of letting it pool on a flat lid. That means less water drips into the bin through the main opening, and the bag or waste inside stays drier than it would in an open or flat-topped can. On a normal rainy day, the dome does its job pretty well.
But “keep rain out” is not the same as “waterproof.” Many public trash cans are designed for easy access, ventilation, and drainage, so they are not sealed containers. Rain can still get in through side openings, push flaps, gaps around the lid, seams, and vents. Wind-driven rain is especially good at finding those small entry points. If the can sits on a sloped sidewalk or gets splashed by passing cars, water can also enter from below or around the base.
The dome also has limits depending on its shape. A shallow dome with a wide mouth may block overhead rain but not angled rain. A deep dome with a small opening performs better, but it can make the can harder to use. Some urban bins have drainage holes so rainwater that does get inside can escape. That helps prevent soggy trash and standing water, but it also means the bin is not trying to be a completely dry box.
So, do domed urban trash cans really keep rain out? They reduce rain exposure and make a real difference, especially compared with open bins. But they should be understood as rain-resistant, not rain-proof. The best designs combine a good dome, a sheltered opening, tight seams, and sensible drainage—because in a city, rain rarely falls straight down.