Taggart, rain is important in so many ways, for example, helping make the grass green and the gardens grow. So I’m glad you asked why rain happens.
To begin, know that warm air holds quite a bit of water. this is why in the summer it feels so very humid. This warm air rises in the sky and begins to cool.
Several things can make the air rise including fronts, storm systems, mountains and even the jet stream.
This water vapor, which is just invisible water in the air, becomes water droplets or ice crystals as a cloud forms high in the sky.
When enough of these droplets or crystals collect together, we see them as clouds.
If the clouds are big enough and have enough water droplets the droplets merge and form even bigger drops.
When the drops get large enough they fall out of the cloud and you see and feel rain if it reaches the surface before evaporating.
We use radar to see rain. Radar stands for radio detection and ranging. It determines how heavy the rain is and how far it is from the radar.