What does a black cloud in the sky mean?

A black cloud in the sky typically indicates the presence of stormy weather, often associated with rain, thunderstorms, or severe weather conditions. These clouds, known as cumulonimbus or nimbostratus, can carry heavy precipitation and may signal the approach of a cold front. Their color results from the density of water droplets or ice particles within the cloud, which can block sunlight. Observing a black cloud usually suggests that people should prepare for potential storms or inclement weather.