Evaporation happens when the sun heats the earth's waters. The sun heats oceans, rivers, lakes, and ponds. The heated water changes to water vapor. We can't see the vapor. The water vapor moves up into the sky. The water vapor becomes colder and colder. Very cold vapor changes into water drops. The water drops make a cloud. The cloud becomes heavy. Rain or snow fall from heavy clouds. Snow falls if the air temperature is cold. Rain falls if the air temperature is warm.

There are many different clouds.

This is a Cumulus cloud. A Cumulus cloud is large and puffy.

This is a Cirrus cloud. A Cirrus cloud has a thin circle shape.

This is a Stratus cloud. A Stratus cloud looks like a large white blanket.

This is Fog. Fog is a low cloud. Fog is close to the ground. When the weather is foggy, we cannot see faraway.

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Last modified: Fri Jun 13 14:53:34 PDT 1997