There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a equal amount of daylight and darkness at all latitudes. These events are referred to as Equinoxes.The word equinox is derived from two Latin words - aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes. How do the climatological temperature patterns follow the four seasons? The temperatures are pretty much the same when comparing early winter to late winter and pretty much the same when comparing early summer to late summer. However, late Fall is much colder than early Fall and late Spring is much warmer than early Spring. Why is that? The reason is linked to the changing of the solar sun angle during each season. In the Fall, the sun angle is always getting lower and in the Spring it is always getting higher. From this it would make sense that late Fall is much colder than early Fall and late Spring is much warmer than early Spring. In the winter, the sun angle is INCREASING and in the summer the sun angle is DECREASING. This fact causes temperatures to be pretty much the same when comparing early winter to late winter and pretty much the same when comparing early summer to late summer. The cumulative cooling of the ground and ocean is partially offset by an increasing sun angle in the winter and the cumulative warming of the ground and ocean is partially offset by a decreasing sun angle in the summer. This causes the Spring and Fall seasons to seem much quicker in duration than the Summer and Winter seasons.
