Precipitation (disambiguation) facts for kids

Precipitation is any kind of water that falls from the sky to the Earth's surface. This includes things like rain, snow, sleet, and hail. It's a very important part of Earth's water cycle, bringing fresh water to our planet.

What is Precipitation?

Precipitation happens when water vapor in the atmosphere cools down and turns into liquid water or ice crystals. These tiny droplets or crystals then grow larger until they are too heavy to stay in the clouds. At that point, they fall to the ground as precipitation.

How Does Precipitation Form?

It all starts with the Sun. The Sun's heat causes water from oceans, lakes, and rivers to evaporate. This means it turns into an invisible gas called water vapor and rises into the air.

As the water vapor rises, it cools down. When it gets high enough, it condenses, meaning it turns back into tiny liquid water droplets or ice crystals. These droplets and crystals gather together to form clouds.

Inside the clouds, these tiny water droplets or ice crystals bump into each other. They stick together and grow bigger and bigger. When they become heavy enough, gravity pulls them down to Earth as precipitation.

Types of Precipitation

There are several different types of precipitation, depending on the temperature of the air and the clouds.

Rain

Rain is the most common type of precipitation. It happens when water droplets fall from clouds and reach the ground as liquid water. This usually occurs when the air temperature from the clouds all the way to the ground is above freezing (0°C or 32°F).

Snow

Snow forms when water vapor in clouds turns directly into ice crystals. These crystals stick together to form snowflakes. Snow falls when the air temperature from the clouds to the ground is at or below freezing. Snowflakes have many beautiful and unique shapes.

Sleet

Sleet is a mix of rain and ice pellets. It forms when snowflakes fall through a layer of warm air and melt into raindrops. Then, these raindrops fall through a layer of freezing air closer to the ground. They refreeze into small ice pellets before hitting the ground. Sleet often bounces when it lands.

Freezing Rain

Freezing rain is rain that freezes on contact with surfaces. It starts as snow, melts into rain, and then falls through a very thin layer of freezing air right at the ground level. The raindrops don't have time to freeze in the air. Instead, they freeze instantly when they touch cold objects like trees, roads, and power lines, creating a layer of ice. This can be very dangerous.

Hail

Hail consists of balls or lumps of ice. It forms inside strong thunderstorms. Water droplets are carried upward by strong winds (updrafts) into very cold parts of the cloud, where they freeze. They then fall, collect more water, and are pushed back up again, adding more layers of ice. This process repeats until the hailstone is too heavy for the updraft to support, and it falls to the ground. Hailstones can range in size from small peas to golf balls or even larger!

Why is Precipitation Important?

Precipitation is vital for life on Earth. It provides fresh water for drinking, farming, and for all plants and animals. Without precipitation, our planet would be a dry, barren place.

It helps fill up rivers, lakes, and underground water sources. Farmers rely on rain to grow crops that feed people and animals. It also helps clean the air by washing away dust and pollutants.

However, too much precipitation can cause floods, and too little can lead to droughts. Scientists study precipitation patterns to understand our climate and predict weather.

See also

• Quantitative precipitation forecast