The heat from the Sun makes water from rivers, lakes, seas and oceans evaporate. This water vapour rises up into the sky and when this meets colder air, it condenses and forms a cloud.
Shapes of clouds
Small clouds, white, thin and sometimes in strips, which may indicate rain.
Clouds made up of small crystals of ice. These clouds indicate cold weather.
An expanse of white or grey clouds which brings rainfall.
These have an irregular shape, and can be white, greyish, in layers or all over.
Cloud in the form of see-through layer and can be a sign of rain or snow.
Typical rain clouds, dark and grey.
Grey clouds, round and width bulges. They bring light rain.
A low grey, thick layer of cloud bringing drizzle and sleet.
White clouds, piled up high in the sky. Small sized cumulus clouds indicate fine weather.
This looks like a tower, dark at the base. It brings storms.