Which cloud is often considered a sign of fair weather?

Correct answer: Small white cumulus clouds

Correct answer: A, small white cumulus clouds. Fair-weather cumulus clouds are usually separate, bright or white, and have rounded heaps with relatively flat bases. They can form when local warm air rises and condenses, but they do not necessarily develop into rain-producing storms. B and D describe dark or dense rain-bearing cloud conditions, which are more likely to indicate precipitation or overcast weather rather than fair weather. C, cumulonimbus, is a deep vertical cloud associated with thunderstorms and strong showers, so it is not the usual sign of settled fair weather. The word “often” matters: small cumulus clouds are a common fair-weather sign, not an absolute guarantee that no rain will ever occur. Memory cue: fair-weather cumulus looks like small white cotton heaps; towering dark cumulus signals worsening weather.