How are rain and snow formed?

Water droplets and ice crystals swirl around  

inside the cloud.  

They gradually join into larger drops.  

One cloud drop must increase by almost a million times to  

create a raindrop.  

 

The temperature of the air and the strength of the thermals in the cloud  

control how much water can be held in the cloud.  

When the drops get too large to float,  

they fall to the ground.  

 

On their way through the layers of warmer air,  

the ice crystals melt  

and the drops increase in size.  

It rains.  

If it is cold all the way down to the earth,  

the rain falls as snow instead.