Why does it rain - where does it come from? How to explain to a child why it is raining? Reasons for heavy rains
Every person has experienced this natural phenomenon. We all hid from the rain under umbrellas many times and have long been accustomed to checking if there are clouds in the sky before a walk. And the most curious are sure to ask the question, where does this rain come from?
Where does the water for rain come from in the sky?
It turns out everything is very simple. Under the influence of solar heat, the smallest droplets of water evaporate from the surface of the Earth. These droplets are very small, almost invisible to the eye, such small droplets are called water vapor.
Water evaporates from the leaves of trees, from the surface of the earth and even from the surface of our body. Most of the water, of course, evaporates in the form of steam from the water surface of rivers, lakes, seas and oceans.
Evaporation over water can be seen in the early morning, when the vapor begins to collect in droplets right above the water. And you can also see such steam when the kettle boils.
Rising higher and higher, the vapor enters the cold layers of the atmosphere and collects in water droplets and tiny ice floes. After all, the temperature at the top, where the clouds gather, is about zero degrees. The wind collects droplets into huge bizarre clouds. You can see before the rain how white clouds gather into a cloud before our eyes darken. This is because there is so much water in the sky that it blocks out sunlight.
It happens that droplets freeze due to low temperatures and, together with raindrops, fall to the ground. It's hailing.
The droplets in the cloud connect with each other, become heavier and begin to fall to the ground. So it starts to rain.
Why does it rain more often in autumn?
Rains in Russia in autumn are even less frequent than in summer. According to weather forecasters, the largest amount of precipitation falls in June. And in autumn, due to the large number of cloudy days, it seems to us that autumn is rainy.
In winter, evaporating water vapor does not even have time to gather into droplets, but immediately turns from steam into fluffy snowflakes. Yes, snowflakes are formed from steam. And then instead of rain in winter it snows.
Now you know how water gets into the atmosphere and why it rains. Once on the ground in the form of rain or snow, water goes into groundwater, into the seas, oceans, rivers, lakes, and other bodies of water, and everything starts again and again. This natural phenomenon is called the water cycle.
Without such a water cycle, our planet would turn into a lifeless desert.
You can arrange a small water cycle even at home. For this transparent cover and put on fire. You will see how the steam will rise, settle on the lid, in the form of droplets. And the drops will fall down to rise up again, turning into steam. Such a wonderful rain in a saucepan.
Children are very fond of frolicking in the summer rain, walking in puddles, measuring their depth, and launching boats in murmuring streams. And in childhood, everyone, without exception, worries question – why is it raining?
When the sky is covered with gloomy, dark clouds, the drops in them become heavier and larger. Not staying in the air due to their own weight, the drops fall to the ground - it's raining.
Where and why is there water in the sky, in clouds and clouds?
There is a lot of water on earth - it is found everywhere: in lakes, rivers, seas, in the leaves of trees, even the human body consists of 80% water. Under the influence of solar heat, this moisture begins to evaporate from the surface of the earth. Very small droplets of water evaporate - so small that they are almost invisible - these droplets are called water vapor. Most of the water evaporates from large lakes and rivers.
How evaporation occurs can be seen in the early morning - smoky white steam begins to creep over the river, sometimes it is also called fog. Also, when a kettle or pot of water boils, the water evaporates, forming steam.
The answer to the question - why does it rain: the water cycle in nature
Evaporating, water droplets rise higher and higher into the sky, and the wind collects them into whimsical snow-white clouds. Over time, there are more and more water droplets in the cloud, and due to the large amount of water, the cloud stops transmitting sunlight. It is getting bigger, darker and heavier and is no longer called a cloud, but a cloud. And from this cloud, heavy drops of water, connecting with each other, fall to the ground in the form of rain.
Sometimes, when it is very cold upstairs, the droplets freeze and fall in small pieces of ice - this is called hail.
In winter, due to frost, the steam does not even gather into droplets, but immediately becomes snowflakes, which have the most varied shape. In winter, it does not rain - instead of water, such fluffy snowflakes fall on the ground.
Evaporating water falls into the clouds, from there again to the earth, in the form of rain, snow or hail, hitting the soil, the water goes into underground water, saturating rivers, lakes, seas. This cycle is called water cycle in nature.
At home, you can conduct such an experiment: put a saucepan with a transparent lid filled with water on the fire. Evaporating, water, in the form of steam, will rise to the top, remain droplets on the lid, and then fall down, subsequently evaporating again. So at home you can make your own rain, and observe the water cycle in nature.
We listen to the weather forecast every day to find out if it will rain today, and whether it is worth taking an umbrella with us to hide from the rain and not get wet. Many of us like to walk in the rain, fall asleep to the sound of rain, while others, on the contrary, try to hide at home at the first drops of rain, they cannot stand the slush and dampness that rains bring.
The first spring rains awaken nature, fill the earth with life-giving moisture, and dissolve the dirty remains of snow. On hot summer days, rains freshen the air, wash dust off the leaves of trees.
Rain is atmospheric precipitation that falls from clouds that float across our sky. Clouds can have a wide variety of shapes, they look like huge pieces of cotton wool or giant waves, sometimes they resemble bird feathers. Sometimes the sky is covered with a huge black cloud or a solid gray veil.
How clouds are formed
Clouds form in the sky and are made up of water droplets and ice crystals. How do water droplets and ice crystals get into clouds? By heating the surface of the earth, the sun's rays evaporate a large amount of moisture, which rises into the air in the form of water vapor.
Also, water vapor rises from the surfaces of reservoirs: rivers, seas, lakes. All plants of the Earth, from the smallest blade of grass to a huge tree, evaporate water, and animals and humans exhale water vapor.
The higher the temperature and humidity of the air, the more water vapor is formed, which condense and turn into tiny droplets of water. From these small droplets of water, as well as from ice crystals, if the air is cold, clouds form. 
Not every cloud makes it rain. In order for the cloud to rain, the water droplets must become larger. In clouds, the size of the droplets gradually increase - water vapor is deposited on small droplets from the air and the droplets become larger, the same droplets move in the cloud in all directions, collide with each other, merge and increase.
If the cloud consists only of water droplets, then the process of formation of a rain cloud is very slow. Mixed clouds, the upper part of which consists of ice crystals, and the lower part of water droplets, form rain clouds faster, because, falling into the lower layers of the atmosphere, where the temperature is above zero, the ice crystals evaporate and turn into large drops of water. Mixed clouds fall to the ground in the form of heavy rains and even showers. Cumulonimbus, stratocumulus, stratocumulus, stratus and altostratus clouds refer to rain clouds.
What are the rains
Rain is water droplets that are very small less than 0.5 mm and larger, reaching a size of 6-7 mm. Rain is atmospheric precipitation that falls from spring to autumn. On rare occasions, it can also rain in winter. Scientists divide precipitation into three types: it is drizzling, overflowing and torrential rains.
The rest of the people give rains a variety of definitions - warm and cold, long-awaited and boring, short-term and protracted.
It often rains with hail, with snow, with a thunderstorm. Rain can be blind or mushroom, and even icy, but also radioactive and acidic, exotic and even stellar.
Drizzling rain, drizzle
When it is drizzling, it is impossible to get wet under such rain, but dampness hanging in the air is felt. Drizzling rain - rain with small and frequent droplets, it is almost invisible, small droplets, falling on the surface of the puddle, do not form circles. Drizzling rains reduce visibility and make the day foggy.
Drizzle is very small drops no more than 0.5 mm, which seem to hang in the air, as they have a very low falling speed, drizzle also falls during fog. With drizzle, drops are not visible, and the air itself seems damp, wet.
Heavy rain, rain with thunder and hail
Storm clouds are formed when cold air meets warm air masses, as well as the cause of heavy rains is intense heat, moist soil warms up very much, and the moisture that evaporates from the earth's surface forms heavy clouds overloaded with water. Many of us have observed these evaporations, the damp earth seems to be smoking.
Heavy rains begin suddenly, and just as suddenly end. They usually do not last long, but can be very strong. 
Thunderstorm rains are always torrential, they also appear suddenly, accompanied by strong winds, thunder and lightning, they can fall on a certain part of the city, and do a lot of trouble.
These are uprooted and fallen trees, overturned billboards, broken wires, demolished roofs, flooded streets and house entrances, and the downpour bypassed other areas of the city, not a single drop of rain fell there.
Lightning accompanying thunderstorms, falling into residential buildings, causes fires, breaks trees, sometimes lightning hits animals and people.
Tropical showers continue for hours, and a huge mass of water pours onto the ground. Often heavy rains cause floods, rivers overflowing with water, water flows wash away dams and dams, flood settlements, destroy houses, roads, bridges, mudflows come down from the mountains, landslides occur. People often become victims of floods.
Rains with hail occur only in hot weather, when the air is filled with a lot of moisture. Hailstones are formed in cumulonimbus clouds, and when they reach large sizes and cannot stay in suspension, they fall to the ground in the form of hail. The hail has various sizes from a small pea to the size of a chicken egg.
Large hail can pierce the roofs of houses, break glass, and even kill animals and people. Yes, and small hail brings great damage to agriculture, destroys crops in vegetable gardens and fields, damages orchards.
Blind or mushroom rain
Blind rain or mushroom rain occurs in summer, during such rain the sun shines in the sky, and such rain is also called solar rain, after a sunny rain a rainbow necessarily appears.
To fall under such a rain, and even seeing a rainbow, is considered a good omen. Also, according to folk signs, mushrooms begin to grow after the rain - hence the name - mushroom rain. This is a warm and short rain.
Heavy or prolonged rains
Heavy rain can last from several hours to several days. During prolonged rains, the entire sky is covered with clouds, the sun does not peep through the clouds, the day becomes dark, gloomy. Long rains, especially in autumn, are accompanied by a decrease in air temperature. These are cold rains, tedious, annoying, turning all the colors of the world around into dull, gray colors.
freezing rain
Freezing rain occurs when the air at the surface of the earth has a lower temperature - (from 0 degrees to - minus 10 degrees) than in the upper atmosphere. Raindrops, falling into the cold air, are covered with an ice crust, inside the crust the water remains in a liquid state.
Falling to the ground, such ice balls break and the water, flowing out, instantly freezes. Getting on tree branches, wires, surrounding objects, freezing rain gives objects and trees a fabulous unusual look, each branch is covered with an ice crust, and sidewalks and roads turn into an ice rink.
This natural phenomenon looks beautiful, but dangerous, as wires break under the weight of ice, branches break, pedestrians are injured.
Acid and radioactive rain
Acid rain is rain that contains acids and toxic substances released into the atmosphere from harmful industrial enterprises and automobile exhaust. Industrial production pollutes the air with harmful gases that rise up and fall into the clouds, combining with water droplets - form acid. And acid rain falls on the earth, bringing only harm to all life on Earth. Acid rain destroys crops, destroys fish in reservoirs.
Radioactive rains carry an even greater danger - the background radiation increases, which leads to genetic mutations and diseases of internal organs, to oncology and damage to the skin. The reason for the occurrence of radioactive rain are accidents at nuclear power plants, at enterprises that use radioactive substances in the production and testing of nuclear weapons.
exotic rains
Exotic rains are unusual rains, wonderful, mysterious. Rains, which, together with water, bring various objects to the surface of the earth: coins, grain, fruits, and even spiders, fish, jellyfish and frogs.
Sometimes raindrops are painted in different colors - blue, red. Why does it rain so much? Often on hot summer days, dust whirlwinds can be observed above the earth's surface. Rotating, this air column draws in various small debris - pieces of paper, wood chips, plastic bags, even plastic bottles and raises it all above the ground.
More powerful tornadoes are capable of lifting large, heavy objects into the air, and if such a tornado passes over the surface of reservoirs, then, together with water, it sucks in and lifts living creatures that live in water high into the air. The wind blowing in the upper layers of the atmosphere carries tornadoes and whirlwinds over long distances, and when the strength of the wind weakens, “gifts from heaven” fall to the ground along with rain, and sometimes without rain.
Why do colored rains come? The wind raises the pollen of plants high into the sky, and the pigment contained in the pollen paints the rain in different colors - blue, green, yellow. Also, a whirlwind can suck water from a swamp, in which there are large quantities of tiny microorganisms that give the water a brown, red color, or, passing over a desert, raise a lot of multi-colored dust into the air.
Star and meteor showers
Star rain is a starfall, or rather, these are meteoroids that fly into the atmosphere of our Earth and reach speeds of up to tens of kilometers per second, when rubbing against the air, they heat up and begin to glow, and then collapse. Such a phenomenon can be observed at a certain time, at night, it seems that the stars are falling. People often make wishes when they see shooting stars.
A meteor shower or rock shower is a rain that consists of many meteorites. When a large meteorite is destroyed, both large and small fragments fall to the ground. Large meteorites, hitting the surface of the Earth, explode and form meteorite craters. It is believed that about a thousand small meteorites fall on our planet every day.
Why bubbles form when it rains
Raindrops, falling into puddles, hit the water, splash out on top of the water surface, and the air that has fallen under the water film forms bubbles. Larger and more noticeable bubbles form when there is heavy rain with large drops or a downpour.
There is such a popular sign that if large bubbles form in the puddles, it means that the rain will end soon. The sun will shine brightly and the sky will turn blue-blue.
Rain is one of the most common weather phenomena. However, not everyone knows why it is raining, although this information was given by teachers in elementary grades. The global water cycle begins with thermal effects. Under the scorching rays of the sun, liquid evaporates from the surfaces of reservoirs, rivers, seas and oceans. It turns into steam and rushes up. In countries with high humidity, small bubbles can be easily seen.
Reasons for the appearance
The sciences that study any kind of precipitation are called meteorology and climatology. They identify 4 main reasons:
- Elevated landforms.
- Ascending movement of air masses.
- The presence of water vapor, which contributes to the formation of precipitation in the form of rain.
- Meeting and interaction of flows of cold and warm air.
You can conduct a small experiment at home and see clearly how the world water cycle occurs.
To do this, you need to take a small container, draw water into it and put it on the fire to boil. Cover the pot with a transparent lid. When the liquid heats up, it will begin to turn into steam, and small droplets will begin to accumulate on the surface of the lid, and then fall back into the pot of boiling water and turn into steam again.
Upward movements
The sun's rays heat the earth, and the process of evaporation of moisture begins. This happens not only with soil, but also with water surfaces. The evaporated liquid is in the air. According to the laws of physics, warm air moves to the upper atmosphere along with the water bubbles it contains.
Basic physical concepts- absolute humidity (the amount of steam that is contained in the air at the current moment) and relative (in relation to the humidity that is observed at a given temperature). The hotter the air, the more water vapor it contains.
All air currents contain moisture, but the higher it rises, the lower the air temperature becomes. It starts to condense and clouds appear in the sky. When the temperature reaches the lower mark, and the cloud is no longer able to hold the amount of moisture that it contains, it starts to rain.
The process is similar to what happens with ascending air masses. The precipitation rule only works if there is a place for water bubbles to come from - from a leaf plate, water surface, freshly plowed soil, etc.
But if a person is, for example, in the Sahara desert, the sun's rays will not cause rain, since moisture has nowhere to come from.
After the director of one of the American radio stations got wet to the skin, falling under the autumn rain, the program "Weather Forecast" appeared on the air, which had not previously existed. The information turned out to be relevant, because it will never be superfluous to find out whether it is worth taking an umbrella today and whether you need to leave the house, since, for example, in Portugal, rain and wind are a good reason not to show up for work.
Rain is one of the types of precipitation that falls mainly from nimbostratus and altostratus clouds in the form of water droplets with a diameter of 0.5 to 7 mm. Rain usually comes from mixed clouds containing supercooled droplets or ice crystals.
Raindrops fall when small spherical water particles coalesce into larger ones, or when they freeze to an ice crystal. Unlike the generally accepted opinion, they do not have the shape of a teardrop, since they are flattened on the underside due to the pressure of the oncoming air flow.
At first, these droplets are light enough that the air allows them to remain in the cloud. Since inside the cloud they are constantly moving and colliding with each other, merging and increasing in size, they begin to gradually sink down, continuing to increase. This process continues until the water particles gain the required mass, enabling them to overcome air resistance and shed raindrops on the ground.
If water particles are in clouds, inside which the temperature is high enough not to turn into ice crystals, the droplets merge with each other constantly and extremely intensively. It does not rain as often from them as from clouds, inside which the temperature is below zero: in order to fall out of the cloud, ice crystals gain the necessary mass quite quickly.
If at this time there is a very high difference in temperature between the cloud and the earth's surface, then the frozen crystals melt before reaching the earth's surface - and raindrops fall on the ground (the largest drops are obtained when hail melts).
Interestingly, the larger the raindrops, the stronger the rain, but usually it passes rather quickly. The speed of such precipitation can be from 9 to 30 m/s (this is usually typical for summer or spring rain). But if the raindrops turn out to be small, then such precipitation can last for several days or even weeks - water flies to the ground "slowly", at a speed of 2 to 6.6 m / s, which is typical for autumn rains.
Precipitation intensity
One of the important indicators of the amount of precipitation in nature is the fixation of the intensity of rain - the volume of raindrops falling in a certain time.
Rainwater depth is usually measured in millimeters: one millimeter of water is equal to one kilogram of raindrops per square meter (precipitation rate typically ranges from 1.25 mm/h to 100 mm/h). Given the amount of precipitation that falls over a certain period of time, light, moderate and heavy rain are distinguished.
Heavy rainfall
At a speed of 2.5 mm/h, light rain falls regardless of the time of the year at positive temperatures in temperate and high latitudes from dark altostratus, stratonimbus and cumulonimbus clouds. Heavy precipitation lasts from several hours to several weeks and covers a vast territory. If precipitation of this type is prolonged, then they quite often harm nature: the humidity in the atmosphere increases greatly, and plants begin to rot due to oversaturation with moisture.
Drizzling precipitation
Moderate rains come at a speed of 2.5 to 8 mm/h in the form of small droplets from stratus and stratocumulus clouds. These precipitations do not last long, from several hours to two days, their amount is minimal, and therefore the rain does not have a negative impact on nature.
heavy rainfall
Heavy precipitation is heavy rain with wind, which often falls in temperate latitudes, usually in the warm season. Such heavy rain is characterized by a high rate of precipitation (more than 8 mm/h) and a short duration, no more than a few hours. The exception is May rain, which can last up to three days, as well as heavy rainfall in tropical and equatorial latitudes. The rainy season here often lasts several months, and heavy rain pours almost non-stop with an intensity of 25-30 mm / min.
It should be noted that a thunderstorm often accompanies heavy rain, so in such weather it is better to take shelter in order to avoid accidents. Interestingly, the occurrence of a thunderstorm is directly related to the Sun - in the middle latitudes, such a natural phenomenon can be observed in the afternoon and very rarely before dawn.
In Europe, the heaviest rain fell on the territory of Germany in the twenties of the last century, when its rates were 15.5 mm / min. As for the heaviest precipitation on a planetary scale, on the lands of Guadeloupe, rain was recorded with an intensity of 38 mm / min.
Heavy rain is often accompanied by thunderstorms and heavy winds, which causes significant harm to both nature and humans. The consequences of such rain and wind are often landslides, floods, soil erosion. Such weather conditions can cause death of a person, as well as cause an ecological disaster. When it comes to heavy rain, it is not so much its duration that is important, but its intensity: the more drops fall, the more detrimental the consequences will be.
rainy season
There are areas on Earth where the most precipitation falls. This phenomenon is known as the "rainy season" and can be observed in tropical and subtropical latitudes. The closer to the equator the rainy season, the more prolonged precipitation, lasting from May to October. In tropical regions more distant from the equator, the rainy season consists of two periods and gives people a certain respite (the rainy belt does not stand still and gradually moves after the zenith of the Sun from the northern to the southern tropic and back).
Tropical summer rain usually begins suddenly, and raindrops, having formed one continuous stream, pour onto the ground in such a dense wall that little can be distinguished at a distance of one meter. As a result, precipitation of such intensity can, in a few hours, not only completely flood cities and villages, but also cause mudflows and floods.
Interestingly, for local residents, the rainy season is a common occurrence, they have long been accustomed to such weather conditions and know how to act, for example, almost all houses in Thailand are built on stilts. That is why tourists are not recommended to visit equatorial and tropical countries during this period. Storms and hurricanes also occur quite often, only in the Philippines in one rainy season about thirty hurricanes and storms fly over the country.
Precipitation in temperate latitudes
The farther from the equator, the weaker the rainy season, and in temperate latitudes it completely disappears: precipitation here is evenly distributed throughout the year and their abundance depends not so much on the Sun, but on winds and mountain ranges. For example:
- Spring rain is typical for the whole territory of Europe and during the first two months the rains constantly alternate with the Sun. Showers often begin in the last days of spring;
- In Germany, warm rain can be observed throughout the summer. In Sweden, Denmark, the Netherlands, on the territory of Central and Eastern Europe, August is considered one of the most rainy months;
- Autumn cold rain is observed in Norway, France, Italy and the Balkans in October and November, when warm weather is gradually replaced by frost;
- Winter cold rain can be seen mainly in the south of Europe - in the Balkans, in the west and south of the Iberian Peninsula, but it is not uncommon for the northern territories, for example, it often falls in Scotland and the Faroe Islands.
rain and nature
The role of precipitation in the life of nature can hardly be overestimated, since they both give life and take it away. Rain and wind, forming squalls, thunderstorms, hurricanes can destroy houses, break crops, nullify all human efforts and even deprive him of life or health. The consequences of heavy rainfall are often catastrophic.
Raindrops also give life: after rainfall, nature is renewed and revived. For example, mushroom rain is eagerly awaited by all mushroom pickers. This is a drizzling warm rain that falls from clouds that are low above the earth's surface during the growth of mushrooms. Interestingly, unlike other precipitation, mushroom rain is short-lived, raindrops wet the soil well, and all mushrooms in the soil begin to grow extremely well.