17. Earth's geographical zones
Climate diagrams
Climate diagrams present the most important things about a place's climate. These things are its monthly average temperature and its monthly precipitation or rainfall. By studying these two factors, we can learn a lot about the climate of a certain place. In climate diagrams, the monthly average temperature is shown as a red line. The line contains dots, which indicate the average temperature for each month. The months are listed from January (J) to December (D) in the bottom of the diagram.
The climate diagram on the right is from Jyväskylä, Finland. It shows that the city experiences a cold winter and plenty of rainfall.
The planet's equator is warmer than its poles
The planet's equator experiences warm weather throughout the year. This is because the Sun shines almost directly at the equator during all seasons.
In the temperate zone, such as in Northern Europe, the Sun's light arrives on the ground in a slight angle. This means that the same amount of sunlight has to cover a larger surface area. The result is a cooler, more temperate climate.
Because the heat provided by the Sun decreases when moving from the equator toward's the planet's two poles, the planet can be divided into four geographical zones.
In the temperate zone, such as in Northern Europe, the Sun's light arrives on the ground in a slight angle. This means that the same amount of sunlight has to cover a larger surface area. The result is a cooler, more temperate climate.
Because the heat provided by the Sun decreases when moving from the equator toward's the planet's two poles, the planet can be divided into four geographical zones.
Geographical zones
The planet's geographical zones.
The planet's geographical zones.
Tropical zone
The tropical zone is located near the equator. This geographical zone includes most of Central America and Southern America between the equator and the Tropic of Capricorn. There are no regions belonging to the tropical zone in Europe.A large part of Africa is located in the tropical zone. The tropical zone is characterized by an eternal summer. The sun shines throughout the year, and there is no variation between seasons.
On the right, you can see the climate diagram from Lagos, Nigeria. Lagos is located on the equator. Notice how stable the temperature graph is throughout the year. This tells us that the city is located on the equator.
Subtropical zone
The subtropical zone is located near the tropics of Cancer and Capricorn. A good example of a subtropical climate zone is found in the Mediterranean region, which includes countries such as Greece, Italy, and Spain.Only a small part of North America is located in the subtropical zone. This part runs through Florida to California. In South America, the subtropical zone encompasses an area between the Andes and the equator.
On the right, you can see the climate diagram of Cairo, Egypt. It is located in Northern Africa, and its climate is characteristic to the subtropical zone. Notice how much the amount of monthly precipitation varies throughout the year. However, even during the rainiest months, the amount of rainfall is still very little.
Temperate zone
Most parts of North America and Europe are located in the temperate zone. The southernmost tip of South America also belongs to the temperate zone. The temperate zone experiences cold winters with occasional snowfall. Summers in the temperate zone are quite warm. The temperate zone experiences four distinct seasons: spring, summer, autumn, and winter.In the temperate zone, the average temperature of the warmest month exceeds +10 degrees Celsius, whereas the average temperature of the coldest month can range between 0-18 degrees Celsius. This means that winter temperatures can vary greatly inside the temperate zone.
On the right, you can see the climate diagram of Paris, France. It is located in the European temperate zone.
Frigid zone
The frigid zone is a geographical zone that is found near the polar regions of planet Earth. The northernmost parts of North America and Europe are located in the frigid zone, as are Greenland, half of Iceland, and the whole continent of Antarctica. There are no areas belonging to the frigid zone in South America.The frigid zone experiences an extremely cold winter every year. The northernmost parts of the region have no summer. Snow rarely has time to melt completely during the summer. The monthly average temperature never rises above 10 degrees Celsius.
The climate diagram on the right is from Vardo, Norway. It is located in the northernmost part of Europe, and its climate is characteristic to the frigid zone.
Terminology
| Term | Explanation |
|---|---|
| climate diagram | A diagram that displays the average monthly temperature and total monthly precipitation of a certain place. |
| climate | A term that describes the yearly climatic conditions (such as average temperature and precipitation) of a certain place. |
| geographical zone | The planet Earth can be divided into four geographical zones based on climatic conditions. |