Why do clouds appear and disappear?

Answer :

Clouds are composed of liquid suspended water droplets in about a 100% RH environment. The three primary ways that clouds dissipate is by (1) the temperature increasing, (2) the cloud mixing with drier air, or (3) the air sinking within the cloud.

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.