Northern Hemisphere

The Northern Hemisphere is the half of a planet's surface (or celestial sphere) that is north of the equator. On Earth, the Northern Hemisphere contains most of the land and population.

In the temperate regions of the hemisphere, winter lasts from around December to February and Summer from around June to August. The earth's perihelion, during which its orbital motion is fastest, occurs in January, and therefore northern hemisphere winters tend to be shorter and less severe than southern hemisphere winters at equivalent latitudes. Tropical regions tend to experience a rainy season during the 'summer' months, and a dry season during the 'winter' months.

Regions north of the Arctic circle will experience 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.

In temperate and polar regions of the Northern Hemisphere most of the year, the sun passes from east to west in the south, causing sun-cast shadows to turn clockwise through the day. In the tropics, the sun is always virtually overhead, but will sometimes be in the south and sometimes in the north.