The weather is the condition in the sky. The earth is surrounded by an envelope of air, the atmosphere. Weather means what happens in this atmosphere at a certain place and at a certain time. Climate, on the other hand, means whether a place is normally rather warm or rather cold, on average over many years.
Weather includes wind, storms, rain, snow and much more. All of this is caused by the sun. The heat of the sun over the sea causes water to evaporate and the moisture to rise into the air. This later becomes clouds. Wind is caused by the fact that there is warmer air in some places than elsewhere.
When people talk about good weather, they usually think of sunshine. But for farmers, for example, it is important that the weather changes. In agriculture, you sometimes need sunshine, but sometimes you also need rain so that the plants get enough water.
Because the weather is important to many people, they have always wanted to predict it. Today, this is done by a science of its own, meteorology. Almost everywhere in the world there are weather stations where the wind, rain and other things are measured. With this knowledge, it is quite easy to calculate where and when it will rain over the next few days. The word weather refers to the weather in a certain period of time in a certain area.