What Is , the Autumnal Equinox?.<br />The autumnal equinox, also known as the<br />September equinox, occurs the moment<br />the sun crosses the celestial equator.<br />During the day this occurs, the length of night<br />and day are nearly equal, as the sun is shining<br />directly perpendicular to the equator. .<br />It is for that reason we call it an “equinox,” which<br />is derived from the Latin word for “equal night.”.<br />The September equinox occurs <br />on either the 22, 23 or 24 of <br />the month.<br />This year’s equinox occurs on Sept. 22 at around 9:30am EST.<br />For the Northern Hemisphere, this signals<br />the first day of fall, while in the Southern<br />Hemisphere, it signals the first day of spring.<br />Earth’s axis is typically tilted at a 23.4 degree<br />angle, which means either the southern or northern hemisphere is more tilted towards the sun.<br />During that time period and until the equinox,<br />that hemisphere receives more sun than the other,<br />causing the varying seasons of winter and summer
