The Northern Hemisphere is the half of a planet that is north of the equator—the word hemisphere literally means 'half ball'. It is also that half of the celestial sphere north of the celestial equator. Earth's northern hemisphere contains most of the land and most of the human population (about 90%).
Geography and climate
Due to the Earth's axial tilt, winter lasts from the winter solstice (typically December 22) to the vernal equinox (typically March 20) whilst summer lasts from the summer solstice (typically June 21) through to the autumnal equinox (typically September 21).
The Arctic is the region north of the Arctic Circle. Its climate is characterized by cold winters and cool summers. Precipitation mostly comes in the form of snow. The Arctic experiences some days in summer on which the sun never sets, and some days in winter on which the sun never rises. The duration of these phases varies from one day for places right on the Arctic Circle to several months near the North Pole itself.
Between the Arctic Circle and the Tropic of Cancer lies the Northern Temperate Zone. The changes in these regions between summer and winter are generally mild, rather than extreme hot or cold. However, a temperate climate can have very unpredictable weather.
Tropical regions (between the Tropic of Cancer and the Equator) are generally hot all year round and tend to experience a rainy season during the 'summer' months, and a dry season during the 'winter' months.
Hurricanes and tropical storms spin anti-clockwise in the northern hemisphere due to the Coriolis effect. In contrast they spin clockwise in the southern hemisphere. The shadow of a sun dial moves clockwise in the northern hemisphere (opposite of the southern hemisphere). During the day the sun tends to raise to its maximum at a southerly position, where as in the southern hemisphere it raises to a maximum that is northerly in position (as it tends towards the direction of the equator). In both hemispheres the sun rises in the east and sets in the west.
Also the Moon appears "upside down" compared to a view from the southern hemisphere and the view of the stars is much different. The North Pole faces away from the galactic centre of the Milky Way, this results in there being far fewer and less bright visible stars in the northern hemisphere compared to the Southern Hemisphere, making the northern hemisphere more suitable for deep-space observation as it is not 'blinded' by the Milky Way.
List of continents and countries
- entire Asia except most of Indonesia
- entire Europe
- entire North America
- A small part of South America, north of the Amazon River
- About 2/3 of Africa, north of the Congo River
South American countries
- Countries primarily in the northern hemisphere
- Merriam Webster's Online Dictionary (based on Collegiate vol., 11th ed.) 2006. Springfield, MA: Merriam-Webster, Inc.