Not necessarily—but I wouldn’t treat that as a free pass to leave them outside all the time. In an urban setting, the answer usually depends on your cushions, your exposure, and your routine.
If you have quick-drying, mold-resistant cushions and a covered balcony or terrace, you can often leave them out for stretches. But overnight dew is the sneaky issue. It can soak into seams and foam, and in a city where airflow is limited and dust settles quickly, that moisture hangs around longer than you’d expect. Add rain, humidity, pigeons, pollution, or construction dust, and “leave it out every night” starts to look less convenient and more expensive.
I’d bring them in or put them in a storage box when rain is likely, when the cushions are already damp, during high-humidity stretches, or if you live on a ground-floor patio where theft or stray animals are a concern. If your cushions are not labeled quick-dry or mold-resistant, I’d be more careful. Thick foam cushions that hold water are the ones that tend to get musty and sag over time.
That said, hauling cushions inside every single night can be unrealistic. A practical middle ground is to use a waterproof cover, elevate the cushions so water can drain, shake off debris, and store them in a deck box when wet weather is coming. Let them dry fully before stacking or covering them, because trapping moisture is worse than a little fresh air.
So, do urban outdoor furniture cushions need to be brought inside every night? No, not always. But they do need a smart routine. If you want them to last, treat them like outdoor gear: protect them from prolonged wetness, heavy dirt, and theft risk, and bring them in when conditions are rough rather than waiting for a problem to show up.