People often get climate and weather confused. "Climate is what we expect, weather is what we get," said John Herbertson. He was a British geographer more than 100 years ago.
The difference is time. Climate is the pattern of weather over a long period. It tells us if an area is rainy during certain seasons, for example. Weather describes a shorter period. A weather report might tell us if it's going to be sunny today.
Different parts of the world have different climates. For example, northern Canada has a polar climate. It is usually cold and snowy. Central America, near the equator, has a tropical climate. The equator is the line that runs along the middle of a world map, from left to right.
Many measurements help describe the climate of an area. Temperature">Temperature measures how hot or cold an area is. Precipitation measures the amount of rain and snow. Other measurements are windiness, humidity, cloudiness, pressure, and fog. Distance from the sea and the seasons also affect the climate.
Climate is created by a region's climate system. A climate system has five parts. These parts are the atmosphere, the hydrosphere, the cryosphere, land surface, and the biosphere.
The atmosphere is made up of the gases around Earth. They include the air we breathe. Gases move around in currents of air. They have the biggest effect on weather and climate.
The hydrosphere is made of Earth's water. It includes the oceans and lakes.
The cryosphere is made of glaciers and other types of ice.
Land surface also affects climates. It includes mountains, deserts, and other types of land.
The biosphere is made of all living beings on Earth. Plants and trees use and create gases in the atmosphere. Animals, especially humans, have an effect on weather too. For example, people build cities. Streets and buildings trap the heat from sunlight. That is why cities are usually hotter than the area around them.
Wladimir Köppen was a scientist who studied climates. In 1900, he and other scientists said there were five main types. The types are tropical, dry, mild, continental, and polar.
Rainforests are places with a tropical wet climate. They have warm temperatures and heavy, regular rain. The coolest temperature is between 20° to 23° Celsius (68° and 73° Fahrenheit). Afternoon temperatures usually reach 30° to 33° Celsius (86° to 91° Fahrenheit). The seasons and temperatures don't change much during the year.
Tropical wet climates are around the equator. The U.S. state of Hawai'i has a tropical wet climate.
Tropical monsoon climates are mostly in southern Asia and West Africa. A monsoon is a group of winds that flip direction every six months. Monsoons usually go from sea to land in the summer. They go from land to sea in the winter. Summer monsoons bring large amounts of rain with them. The countries of India and Bangladesh are famous for their monsoon climates.
Tropical: Wet and Dry
Tropical wet and dry climates sit just near the equator. They create grassy plains called savannas.
In this climate, there are three seasons. One is cool and dry. Another one is hot and dry. A third season is hot and wet.
When there isn't much rain, people and animals go through drought">drought. That means it's very hard to find water to drink.
Dry: Arid and Semiarid
In the dry climate areas, there isn't much precipitation. The two dry climate types are arid and semiarid.
Temperatures in dry climates change a great deal during the day. They also change between seasons. The hottest spots in the world are in arid climates. The temperature in the Death Valley National Park, California, reached 56.7° Celsius (134° Fahrenheit) on July 10, 1913. That was the highest weather temperature ever measured.
Some parts of the world never see rain. One of the driest places on Earth is the Atacama Desert. This is in Chile, a country in South America.
Semiarid regions usually get more rain. They are often between arid and tropical climate regions.
Mediterranean climates have warm summers. They have short, rainy winters. Mediterranean climates are found on the west coasts of continents. They are also along the shores of the Mediterranean Sea. The Mediterranean is the large sea between Europe and Africa. Mediterranean summers have clear skies, cool nights, and little rain.
Mild: Humid Subtropical
Humid subtropical climates are usually on the eastern sides of continents. They include cities like Savannah, Georgia. Here, summers are hot and humid. Winter can be very cold. Hurricanes and storms happen often.
Weather gets cooler away from the equator. The marine west coast climate is typical of cities like Seattle, Washington. It has longer, cooler winters than the Mediterranean climate. Drizzle falls for about two-thirds of winter. Overall temperatures are about 5 ° Celsius (41° Fahrenheit).
Continental: Warm Summer
Areas with continental climates have colder winters and more snow. They are between mild and polar climates. Continental climates go through large changes between seasons. In autumn, forests have bright colors. Then, trees lose their leaves. That is when winter starts.
Thunderstorms and tornadoes mostly happen in continental climates. Warm summer areas often have wet summers. That is why they're also called humid continental.
Continental: Cool Summer
Cool summer climates have cold and snowy winters. Cold winds sweep in from the Arctic.
Subarctic climates are north of cool summer areas. They have very long, cold winters. Precipitation is low. Subarctic climates are also called taiga.
The polar climates are inside the Arctic and Antarctic Circles. These are near the North and South Poles. In tundra climates, summers are short. Temperatures can be as high as 10° Celsius (50° Fahrenheit).
Tundras are filled with life. They have many wildflowers, birds, insects, and fish. Whales feed on tiny creatures in the cold waters. People have learned to live on the tundra for thousands of years.
Polar: Ice Cap
Not many animals survive in the freezing Arctic and Antarctic. Most of the sunlight bounces off the ice. Skies are mostly clear and precipitation is low.
High Elevation Climates
These are the climates discovered by Köppen. Later, scientist Glen Trewartha added two more. He added upland and highland climates. These are called high-elevation climates.
Upland areas are flat and high above the sea. Highland areas are high in the mountains. The higher you climb, the colder the climate gets. Some mountains have a tropical climate at the bottom. But at the top, it feels more like the North Pole.
Effects of Climate
Earth has many different plants and animals. Different climates helped create this mix. Animals and plants learned how to survive in different climates.
Climate also affects humans and how they live. It helps explain the food we eat and clothes we wear. It affects the houses we build too.
Climate changes over long periods of time. Sometimes, though, big changes happen. In 1883, the volcano called Krakatoa erupted in the Asian country of Indonesia. It blasted ash into the atmosphere and blocked sunlight. It changed the global climate for years.
Scientists believe climate change is happening more quickly today. Temperatures are rising. So are the seas. Scientists call this global warming.
Global warming is likely our fault. People have been creating huge amounts of greenhouse gases. These gases come from burning coal, gas, and other fuels. They take in heat from the sun. They hold this heat in Earth's atmosphere.
Higher temperatures can change climates. Warmer air affects air and water currents. It can be difficult for animals to live through such big changes.
Humans may be able to slow down climate change. That's not easy, though. It takes long-term planning.