Summarize variations in climate among three major zones as you travel south from the equator toward the south pole?

Equator area: closest to the sun and hot and humid due to the mass evaporation from the excess heat. 

Mid equator/south pole: somewhat mild, colder, probably mid-humid, depending on which end of the midsection you're going for

South Pole: cold and dry. Cold because it's naturally far away from the sun (like the north pole) and dry because there isn't significant water evaporation here and any that may form crystallizes into snow and ice.