Rain Facts
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.
Fun Rain Facts for Kids
- Raindrops fall at a speed of 5 to 18 miles per hour depending on the size of the raindrops.
- Rain is an essential part of the water cycle.
- Most raindrops are very tiny—no more than ¼ inch in diameter.
- The highest amount of rainfall in one year ever recorded was 467.4 inches in Mawsynram, India.
- 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.
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:
- Snow
- Sleet (slushy, freezing rain)
- Ice (tiny drops of ice that fall like rain)
- Hail
Hail is rain that gets caught in the high upper atmosphere winds of a storm and is 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 and 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.
There is only a partial water cycle: water is delivered to the ground by precipitation while it is retained as clouds in the sky and falls over and through the land.
This is one of the reasons why the earth is cold in winter and warm in summer. Water escapes into the atmosphere and land sinks due to evaporation.
Dirty Rain
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.
Convectional Rainfall
Convectional rainfall takes place when the sun warms the surface of the Earth, causing water to evaporate. This then causes water vapor to form.
When the Earth heats up, it also warms the air above it.
This then causes the air to expand and rise. As the air rises it cools and condenses.
The condensation increases the water vapor concentration, allowing moisture to evaporate more easily and cloud formation.
According to NOAA, on average during June, July and August a major storm moves across Australia. When a storm approaches, it travels as a warm frontal system, moving around the ocean from west to east.
With the thunderstorms passing over land, air carries the warm air from the front into the clouds and gives them condensation.
As the winds change, the cloud base will quickly evaporate. As the cool air reaches the surface, cloud tops are continuously topped with evaporated water vapour.
Relief Rainfall
Relief rainfall is also known as orographic rainfall, it generally occurs in areas where the land increases in height.
Relief rainfall is found in areas where the land moves upward and downward in response to gravity and wind. A wave may break over a few small points, and this movement is called flood or orographic flow.
There are many examples of this phenomenon in various coastal plains of the United States and Canada.
What is the pattern of relief rainfall?
Two effects will result from relief rainfall. On the one hand, it can cause a decrease in the total amount of rainfall.
It can increase the total amount of moisture available for rain.
This moisture is most abundant during high ground, but during the formative process of the precipitation, the movement of water from its base causes more precipitation to occur.
Frontal rainfall
Frontal rainfall occurs when a region experiences a severe precipitation deficit on a sufficient scale, with sufficient duration.
It is the opposite of seasonal rainfall and is mostly dependent on atmospheric circulation.
There are two types of atmospheric circulation:
1) Cyclonic systems: these can be described as being oceanic (the dominant model in Europe) and/or atmospheric (largely on land). Their strength is related to the relative strength of magnetic anomalies, temperature, and wind speeds.
Strong cyclonic circulation systems result in large-scale low-pressure regions of similar size, and therefore can be found on all continents in the Northern hemisphere, and on some in the Southern.
Strong cyclonic circulation brings warm (liquid water), heavy (rock) rain, and snow on normal days, which makes them known as tropical cyclone days.
2) Circulation systems: these are formed in the Atlantic and Pacific oceans (which has separated from the Atlantic and Indian oceans during the last couple of millenniums) and carry warm and moist air from East to West and cold air from West to East.
Such circulation systems are also used for bringing snow, ice, and occasional wet summers in other regions such as Europe and North America.
Generally, as the rotation of Earth continues, the inter-oceanic transfer of heat becomes increasingly weak, as the oceans gradually become more “fueled” by the Sun and consequently less effective at cooling.
Therefore the “seasonal cycles” we are experiencing in the Northern Hemisphere are not caused by a global thermodynamic problem, but by an ecological problem, caused by the present insufficient winds, which have not kept up with the increasingly rapid movements of energy in the ocean.
What is Acid Rain?
Acid rain is caused by tiny amounts of sulfur dioxide released by the burning of fossil fuels. It’s been blamed for not only destroying coral reefs, which play an important part in preventing carbon dioxide from being pumped into the atmosphere, but for causing numerous other effects, such as putting plants at risk of eating the delicate algae that gives them food, causing shrivelling of ocean plankton and causing acidification of the oceans.