Nimbostratus clouds are thick, low-lying clouds that typically cover the sky in a dense, uniform layer. They form between 1,000 and 6,500 feet (300 to 2,000 meters) above the ground and are primarily composed of water droplets, although they can also contain ice crystals at higher altitudes. Nimbostratus clouds are the main cloud type associated with steady, widespread precipitation, such as rain, snow, sleet, or drizzle. These clouds lack the towering, vertical development seen in clouds like cumulonimbus but can cover large areas, blocking out sunlight and creating an overcast sky. Unlike other clouds, which may form and dissipate quickly, nimbostratus clouds can persist for hours or even days, bringing continuous precipitation.
