The earth is divided into four overlapping hemispheres with each representing one-half of the earth. At any given location in the world, you will be in two hemispheres at one time: either Northern or Southern and either Eastern or Western. For example, the United States is in both the Northern and Western Hemisphere. Australia, on the other hand, is in the Southern and Eastern Hemispheres.
Are You In the Northern or Southern Hemisphere?
Determining whether you are in the Northern Hemisphere or the Southern Hemisphere is easy. Simply ask yourself if the equator is to your north or to your south. The Northern Hemisphere and a Southern Hemisphere are divided by the equator.
- All points of Earth that are north of the equator are in the Northern Hemisphere. This includes all of North America and Europe, along with most of Asia, northern South America, and northern Africa.
- All points on Earth that are south of the equator are in the Southern Hemisphere. This includes Australia, Antarctica, most of South America, and southern Africa.
Climate is the biggest difference between the Northern and Southern Hemispheres.
- Along and close to the equator (zero degrees latitude), the climate is very tropical and remains relatively unchanged throughout the year.
- As you move further away from the equator-either north or south-distinct seasons begin to appear.
- Seasons become more extreme as you travel beyond 40 degrees of latitude. This is most notable in the heavily populated Northern Hemisphere as the 40th parallel bisects the United States and runs across Europe and Asia along the Mediterranean Sea.
It is also important to note that the Northern and Southern Hemispheres have opposite seasons. In December, people in the Northern Hemisphere will be in the middle of winter and those living in the Southern Hemisphere will be enjoying summer. It is the exact opposite in June.
The seasonal differences are due to the tilt of the Earth in relation to the Sun. During the month of December, the Southern Hemisphere is angled toward the sun and this creates warmer temperatures. At the same time, the Northern Hemisphere has tilted away from the sun and receives less of those warming rays, which results in colder temperatures.
Are You In the Eastern or Western Hemisphere?
The earth is also divided into an Eastern Hemisphere and a Western Hemisphere. Which hemisphere you are in is less obvious, but it is not difficult. Essentially, ask yourself which continent you're on.
- The usual division of the Eastern and Western Hemispheres is at the prime meridian, or zero degrees longitude, (through the United Kingdom) and 180 degrees longitude (through the Pacific Ocean, near the International Date Line).
- This set of boundaries places Asia, Australia, New Zealand, half of Antarctica, and most of Europe and Africa in the Eastern Hemisphere; the Western Hemisphere includes the Americas (i.e. "The New World"), Greenland, the other half of Antarctica, and the westernmost edges of Europe and Africa.
- Some would rather consider the Eastern and Western Hemispheres to be divided at 20 degrees West (through Iceland) and 160 degrees East (again in the middle of the Pacific Ocean). This boundary creates a slightly neater distinction by keeping Western Europe and Africa in the Eastern Hemisphere.
Unlike the Northern and Southern Hemispheres, these hemispheres have no real impact on climate. Instead, the big difference between east and west is the time of day. As the Earth rotates through a single day, only part of the world receives the Sun's light. For example, while it may be high noon at -100 degrees longitude North America, it will be midnight at 100 degrees longitude in China.