     the southern hemisphere of earth is the half which is south of the equator. it contains all or parts of five continents (antarctica, australia, about 9/10 of south america, the southern third of africa, and some southern islands in asia), four oceans (indian, south atlantic, southern, and south pacific) and most of oceania. several islands off the asian continental mainland are also in the southern hemisphere. due to the tilt of earth's rotation relative to the sun and the ecliptic plane, summer is from december to march and winter is from june to september. september 22 or 23 is the vernal equinox and march 20 or 21 is the autumnal equinox. == geography == === climate === overall may tend to be slightly milder than those in the northern hemisphere at similar latitudes except in the antarctic which is colder than the arctic. this is because the southern hemisphere has significantly more ocean and much less land. water heats up and cools down more slowly than land.   in the southern hemisphere the sun passes from east to west through the north, although north of the tropic of capricorn the mean sun can be directly overhead or due south at midday. the sun rotating through the north causes an apparent right-left trajectory through the sky unlike the left-right motion of the sun when seen from the northern hemisphere as it passes through the southern sky. sun-cast shadows turn anticlockwise throughout the day and sundials have the 
Hemispheres_of_the_Earth