Northern Hemisphere

The Northern Hemisphere is the half of Earth that is north of the equator. It includes most of the land we live on, such as the continents of North America and Eurasia, as well as parts of Africa and a small bit of South America. Because of Earth's axial tilt, the Northern Hemisphere experiences changing seasons. Winter usually runs from around December 21 to March 20, while summer runs from around June 21 to September 23. These dates shift a little each year.

The Northern Hemisphere has less ocean and more land than the Southern Hemisphere, with about 67% of Earth's land sitting here. The way wind and water move around the world affects the weather and climate in this part of the planet. For example, trade winds and ocean currents create patterns that help shape the climate we experience.

For other planets in the Solar System, "north" is defined in relation to a plane called the invariable plane, similar to how we define north on Earth. This helps scientists study and compare different worlds in space.

Geography and climate

The Northern Hemisphere is the half of Earth that lies north of the equator. During the past 2.5 million years, Earth has gone through cold periods called glacials, when large ice sheets covered parts of Europe and North America. These cold times happened roughly every 40,000 to 100,000 years and were separated by warmer periods lasting about 10,000–15,000 years. We are currently in a warm period called the Holocene.

The Arctic, near the North Pole, has very cold winters and cool summers, with snow as the main form of precipitation. Inside the Arctic Circle, the sun does not set for some days in summer and does not rise for some days in winter. Between the Arctic Circle and the Tropic of Cancer lies the Northern temperate zone, where temperature changes between summer and winter are usually mild. Tropical areas, between the Tropic of Cancer and the Equator, stay hot year-round and have rainy summers and dry winters.

In the Northern Hemisphere, moving objects, such as air and water, tend to turn to the right due to the Coriolis effect. This creates clockwise-moving patterns in oceans, like those in the North Atlantic and North Pacific. It also affects weather patterns, with high-pressure systems causing clockwise air flow and low-pressure systems, such as hurricanes and tropical storms, spinning counterclockwise. The sun’s position changes throughout the year, rising to its highest point in the south for most latitudes north of the subsolar point. From the Northern Hemisphere, the Moon looks upside down compared to how it looks from the Southern Hemisphere.

Demographics

As of 2015, the Northern Hemisphere is home to about 6.4 billion people. This makes up around 87% of all the people living on Earth, which had a total population of 7.3 billion at that time.

List of continents, countries or territories, and oceans in the Northern Hemisphere

The Northern Hemisphere includes many parts of the world north of the equator. Some of the continents here are Asia, Europe, and most of North America. Countries such as China, Russia, and the United States are located in this area. The Atlantic Ocean and the Pacific Ocean also have parts that lie in the Northern Hemisphere. This half of the Earth experiences different seasons because of the way our planet tilts on its axis.