Why are there different names for seasons, and when should you capitalize them?
Fall officially began last week, and you might recall that the new season coincided with the time of the autumnal equinox. But you might be wondering what “equinox” means and how the autumnal equinox and the spring equinox compare to the winter solstice and the summer solstice. In this episode we’ll discuss the distinctions and also address the difference between the words “autumn” and “fall” and when to capitalize those and other seasonal words.
Lowercase seasons unless they’re part of a proper name.
An equinox, which literally means an “equal night,” occurs when the sun’s path crosses the plane of the earth’s equator, making day and night of about equal length throughout the earth. This happens twice a year — about March 20 (for the spring equinox) and about September 23 (for the autumnal equinox); those are the dates for the Northern Hemisphere; they’re switched for the Southern Hemisphere. (A helpful visual guide can be accessed at http://www.athropolis.com/sunrise/def-sol2.htm.) The equinoxes are also called the vernal equinox and fall equinox (1).
The word “solstice” means “sun standing" (2). There are two solstices: the summer solstice (on about June 21) and the winter solstice (on about December 21). The solstices refer to the times in the year when the sun’s rays reach their southernmost point on the planet (the Tropic of Capricorn) and their northernmost point on the planet (the Tropic of Cancer) (3).
Another way to look at it is that, in the Northern Hemisphere, “the summer solstice occurs at the point in the earth’s orbit where the earth’s axis of rotation points most TOWARD the sun, and the winter solstice occurs at the point in the earth’s orbit where the earth’s axis of rotation points most AWAY from the sun" (4).
What most people in the Northern Hemisphere probably associate with solstices is that the summer solstice is the day of the year with the most daylight and the winter solstice is the day each year with the least daylight; the opposite is the case for those living in the Southern Hemisphere.
Next: Is There a Difference Between Autumn and Fall?