Southern Hemisphere

Lore & Background

Owing to the tilt of Earth's rotation relative to the Sun and the ecliptic plane, summer in the Southern Hemisphere is from December to February and winter from June to August. The vernal equinox occurs on September 22 or 23, and the autumnal equinox on March 20 or 21. Southern Hemisphere climates tend to be slightly milder than those at similar latitudes in the Northern Hemisphere, except in the Antarctic which is colder than the Arctic, because the Southern Hemisphere has significantly more ocean and much less land; water heats up and cools down more slowly than land. The differences are also attributed to oceanic heat transfer and differing extents of greenhouse trapping. In the Southern Hemisphere, the Sun passes from east to west through the north, and sun-cast shadows turn anticlockwise throughout the day. The Coriolis effect causes cyclones and tropical storms to spin clockwise. The southern temperate zone is nearly all oceanic. Forests in the Southern Hemisphere have special features, including unique beech species or Nothofagus in Chile and Australia, and members of the closely related genera Lophozonia and Fuscospora in New Zealand. Notable animals include the spectacled bear, the only bear species in the Southern Hemisphere, and penguins, one of the most notable animals found almost exclusively there. Australia and Madagascar developed many endemic animals due to geological isolation, including kangaroos, koalas, platypuses, Tasmanian devils, emus, echidnas, quokkas, cassowaries, lemurs, aye-ayes, fossas, indris, sifakas and panther chameleons.

Reader's Guide

The Southern Hemisphere is significant as the less populated and more oceanic half of Earth, containing only 32.7% of the planet's land but 80.9% of its water. Its climate patterns, ocean currents, and seasonal cycles are distinct from the Northern Hemisphere due to the greater proportion of ocean, which moderates temperatures. The hemisphere is home to unique ecosystems and endemic species, particularly in Australia, Madagascar, and New Zealand, which evolved in isolation. Its lower air pollution levels reflect the smaller human population and industrial activity compared to the Northern Hemisphere. The Coriolis effect causes opposite rotation of cyclones, and the Sun's apparent path across the northern sky creates anticlockwise shadow movement. The hemisphere includes 48 independent countries, with Brazil as the largest and Nauru the smallest. Its legacy includes the extinction of the dodo and the development of several domestic dog breeds, as well as the ongoing hope of Bolivia to regain sovereign access to the sea.

Did You Know?

• The Southern Hemisphere contains 80.9% water, compared to 60.7% in the Northern Hemisphere.
• Summer in the Southern Hemisphere is from December to February, and winter from June to August.
• The spectacled bear is the only bear species that occurs in the Southern Hemisphere.