Honestly, I’d say the short answer is: not ordinary urban trash cans, no. A standard street trash can is designed to hold waste, not to protect living animals. It may look like a dry, enclosed space from the outside, but inside it can be dangerous. Small animals could get trapped, cut on sharp edges, exposed to heat or cold, or come into contact with waste, bacteria, and pests. There is also the risk that sanitation workers will empty or compact the bin without knowing an animal is inside.
That said, I have seen a few clever exceptions. Some designers and community groups have created modified bins or “trash can shelters” with a separate, dry, ventilated compartment for small animals. These are usually purpose-built street furniture rather than normal trash cans. In those cases, the shelter part is kept apart from the waste, has an easy escape route, and is cleaned and checked regularly. That kind of design can work as an emergency refuge, but it is not common, and it is definitely not something you should assume a regular bin can do.
So, if you are asking whether you can rely on urban trash cans as emergency shelters for small animals, I would not recommend it. A safer approach is to support proper animal shelters, community cat houses, wildlife boxes, or rescue groups that can provide clean, ventilated, and safe spaces. If someone wants to adapt a bin into a shelter, it needs careful design, regular maintenance, and clear separation from waste. Without that, a trash can is more likely to become a hazard than a safe haven.