Description & Characteristics. Nimbostratus clouds are associated with rainy, dreary days. They’re also responsible for snowy weather. Either way, these clouds are best known precipitation (and might be the cause for your outdoor activities to be postponed).

Though it’s difficult to tell visually, these clouds can be put into the category of multilevel clouds, meaning the base of a nimbostratus cloud can be found relatively close to the ground, but the tops of them can extend upwards into the middle cloud level. The thickness of a nimbostratus cloud helps give it a darker appearance than most.

Of the ten main cloud types, only two are consistent precipitation producers: nimbostratus and cumulonimbus. Nimbostratus are responsible for continuous precipitation where cumulonimbus are more likely associated with more dramatic weather, including quick-hitting extreme downpours. So if it’s raining, and has been raining all day, you’re witnessing a nimbostratus cloud.