In mid-September each year, we greet the fall season with the arrival of the fall equinox (otherwise known as the autumnal equinox). This is the moment when the Sun crosses the Equator, and those of us living in the Northern Hemisphere will begin to see more darkness than daylight. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.