Cumulus

The cumulus, like the cumulonimbus is also a heaped cloud, but they move steadily across the sky with a typical altitude of 2,000 feet (600 metres) above the ground during the winter, and up to 4,000 feet (1,200 metres) in the summer. They can produce light showers of rain or snow, but individual clouds are usually short-lived (15 minutes) and tend to form when the ground heats up during the day and are less frequent towards the end of the day.

This cloud is formed when the ground heats up from the sun, which in turn, warms the air above. A ‘thermal’ is produced when a pocket of warm air is less dense than the cooler air around or above it, and starts to rise. As it does this, the thermal expands and cools sufficiently so that the water vapour condenses into tiny cloud droplets. This air in the cloud will continue to rise until it stops becoming buoyant.

In some high regions, a south-facing slope can act as a good source of cumulus clouds.