Cloud

A cloud is a mass of evaporated water droplets or ice crystals floating in the air.

When the temperature of the air gets cooler, the cloud starts to cause precipitation (rain, snow, hail or sleet). Clouds can also cause dangerous phenomena: lightning and tornadoes.

Clouds maintain the Earth's temperature: they cool down the day's temperature by blocking some of the Sun's heat and they warm up the night's temperature by preventing the heat from escaping the Earth's atmosphere.

Cumulus clouds in the sky.

Types of clouds

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