Rain, rain, go away, come again another day. How many times have you sang that little song when you want to play outside, but can’t because of the rain?
Sometimes the rain makes it impossible to play the soccer game we were excited about or keeps us from spending the day riding rollercoasters and other fun rides at the amusement park, but rain is very important to the earth and to us. Without it we could not survive.
What is rain
Rain is water that falls from the clouds when they get too heavy. To put it another way, rain is actually gravity in motion. Here’s how it works…
The earth’s water cycle pulls water from the ground, rivers, oceans, lakes and streams up into the sky. This is called evaporation. The evaporated water is warm when it leaves the earth’s surface, but the farther up into the sky or atmosphere it goes, the cooler it gets. As it cools, it clumps together. This is how clouds are formed. When the clouds become too heavy or full, and when other things happen with the winds and air in the atmosphere, gravity causes the rain to fall from the sky.
This process is called precipitation.
Rain has more than one name
The precipitation that falls from the sky isn’t always rain, but it is always water. Depending on the temperature of the surface and the air nearest the surface of the earth, rain can also be:
- Sleet (slushy, freezing rain)
- Ice (tiny drops of ice that fall like rain)
Hail is rain that gets caught in the high upper atmosphere winds of a storm and are pushed up to colder air. When it does, it forms into balls of ice that are too heavy to stay in the atmosphere, so they fall to the ground. Hail can be as small as a pea or as large as a grapefruit. It can hail even when it is hot outside because the ice balls are formed so high up in the air.
What does the rain do
The rain waters the earth, refills streams, rivers, lakes, and oceans and provides the moisture trees and plants use to make their food. The water in the oceans is home to millions of sea creatures and the water in the streams, rivers, and lakes are home to the fresh-water fish and other water animals. This water also gives wild animals the water they need to drink.
When we think of rain, we usually think of clear, clean water, but that is usually not true—especially in the city or in places where there are factories that put smoke and other things into the water and/or air.
The dirt, dust, and chemicals in the air (pollution) travel up into the atmosphere during the process of evaporation. These tiny particles become part of the clouds, which also makes them part of the rain that falls. If you collected rain from a quiet forest far away from any buildings and rain from a city, you would see lots of differences in the rain if you were to look at it under a microscope.
Fun rain facts
If it is storming outside or if you see lightning, it is best to stay inside. You must also remember to:
- Raindrops fall at a speed of 5 to 18 miles per hour depending on the size of the raindrops.
- Most raindrops are very tiny—no more than ¼ inch in diameter.
- Rain is also used to create electricity. We call this hydroelectricity or hydropower.
- More rain falls in tropical places than in any other type of climate.
- Desserts get less rain than any other type of climate except the continent of Antarctica. It is the driest continent on Earth.