Franklyn M. Branley - Down Comes the Rain

To Abigail Samoun
M. A. F.

R ain comes from clouds.
It comes from big clouds and little clouds.
It comes from black clouds, white clouds, and gray clouds.

All cloudsbig ones and little ones, gray ones and white
onesare made of billions of tiny drops of water. The
drops are called droplets, because they are so small.
If this is the size of a drop of water, a droplet would be
just a tiny speck, even smaller than this one.

Drop

Droplet

Water droplets come from water vapor. Water
vapor is a gas.
Theres always water vapor in the air, but you cant
SEE it...
... cant SMELL it...
... and you cant FEEL it.

Water vapor is made when water evaporates.
That means the water changes from a liquid to a gas.

In the morning, put a teaspoon of
water in a saucer. By that night, it may
have evaporated into the air!

When wet clothes hang on the clothesline,
the water in them evaporates. The heat from
the sun changes the water drops and droplets
into water vapor.
Just like the heat from the stove changes
water in the kettle to water vapor. If you heat
it long enough, all the water boils away. The
water vapor goes into the air.

Most of the water vapor in the air comes
from lakes, rivers, and oceans. It comes from
the leaves of plants and from the wet ground.

Heat from the sun causes the water
to evaporate. The water changes from
a liquid to a gas and the water vapor
goes into the air.

When you breathe out, you put water vapor into the air. Usually,
you cannot see the water vapor. But it is there.
Sometimes, if its cold, you can see your breath. Thats because
the water vapor condenses. It changes from a gas to a little cloud.

When cows, horses, dogs, and cats breathe out, they put water
vapor into the air, too. On a cold day, the water vapor changes to
droplets and makes little clouds you can see.

You can make water vapor change to
water. Put a lot of ice into a glass of water.

As the glass gets colder, the
outside of the glass gets WET.

Water vapor in the air is
condensing on the glass.

There may be so much
condensation that the glass drips.

Sometimes the glass stays dry.
That means there is not much
water vapor in the air.

The air holds the water vapor. Breezes
carry it from one place to another.
Much of the vapor moves up and away
from the earth.

Water droplets growing
by combining with each
other to form larger drops

Water vapor
condensing to
form droplets

Rising water
vapor
* This is not visible
to the human eye.

Air above the earth is always cold. The
higher you go, the colder it gets. When
air gets cold enough, the water vapor in it
condenses. The vapor changes to water
droplets. The water droplets make clouds.

When clouds are thin and wispy,
they are holding only a little water.

When clouds are thick and dark,
they are holding much more water.

A single droplet is so small you cannot see it. But you can see a
cloud. Thats because there are millions and millions and millions
of water droplets in a cloud.
Inside the clouds, droplets join together to make drops. When
the drops are too heavy to stay up in the clouds, they fall to earth.

The sky is full of them. They fall through the air
and splatter on the ground. They are raindrops.

Sometimes there are only a few small
raindrops that fall slowly. It is drizzling.

Sometimes there are lots of big drops
that fall very fast. Now it is pouring.

Sometimes the drops in clouds