In this topic you will learn about average weather patterns, or climate.

Weather changes from day to day. The average weather pattern of a region is its climate. Climate can be described by the area's temperature, precipitation, winds, distance from a coast, mountain ranges, and ocean currents. Describing the plants of a region can also describe its climate.

Several things affect the climate in an area. Latitude is one factor that affects temperature and pressure. Near the equator, temperatures are high all year and there is much rainfall. Near the poles, temperatures are low and there is not much precipitation. Between these two zones, winters are cool or cold and summers are warm.

The distance to bodies of water affects an area's climate. Because land heats up and cools off faster than water, air temperatures over land are higher in summer and colder in winter than temperatures over water. Winds and ocean currents also affect climate. Winds cause ocean water to move. An area's height above sea level, known as its altitude, will also affect its climate.

Earth's climate depends on the amount of energy received from the Sun and the amount of heat radiated from Earth into space. If the energy gained equals the energy lost, Earth is in radiative balance. The atmosphere affects the heat gained and the heat lost. Clouds and dust reflect incoming energy from the Sun. The atmosphere absorbs some of the energy. Only about half of the Sun's energy that strikes the atmosphere actually reaches Earth's surface.

The atmosphere absorbs most of the heat energy that Earth radiates. This process results in an average Earth temperature of about 14°C (59°F). Earth's atmosphere acts like the glass in a greenhouse. This greenhouse effect is the ability of the atmosphere to let in sunlight without letting heat escape.

Climates have shifted over long periods of time due to changes in sunlight as well as changes in air, ocean currents, and landmasses. This has had an enormous effect upon all life on Earth.

Understanding climates in different areas and how they affect life gives you knowledge that can help you prepare for choices regarding life in these areas.