Weather is what is happening in the atmosphere now, at any place on Earth’s surface. It includes the temperature and whether it is wet and windy, or dry and calm.
The Sun provides the energy that drives Earth’s weather. The Sun heats the air in various parts of Earth’s atmosphere by different amounts. Masses of warm and cold air then move from place to place, creating winds. Winds bring sunny, wet, or stormy conditions. People find out the type of weather to expect in a FORECAST.
A weather forecast is a prediction of weather conditions over a particular area, either for a few days (called a short-range forecast), or for several weeks (called a long-range forecast). The people who study the weather and make weather forecasts are called meteorologists.
Weather forecasts help people to plan—what to wear, when to travel, or which products to stock in supermarkets. Forecasts are especially important for farmers, builders, sailors, and anyone else who works outdoors. Sometimes an accurate forecast may mean the difference between life and death.
Meteorologists receive information about air temperature, wind speeds, clouds, and rainfall from over 50,000 weather stations worldwide—on land and on ships and buoys at sea. The data is fed into huge computers that produce charts and forecasts. These are used, with satellite images, to predict the weather.