On Sept. 22, the autumnal equinox, which signals the start of fall in the Northern Hemisphere, finally brings an end to our long, hot summer on Monday at 2:19 p.m. EDT. This happens at a precise moment each September, typically on the 22nd or 23rd, when the sun is directly above the equator.
According to the National Oceanic and Atmospheric Association, our planet will appear to have no tilt with respect to the sun. Earth's tilt aligns with its cycle around the sun twice a year, in March and September.
Those in the Southern Hemisphere, or south of the equator, will be experiencing the vernal or spring equinox, which marks the beginning of spring on Sept. 22.
Here's a visual guide to the equinox:
The word "equinox" comes from the Latin words "aequalis" and "nox," meaning "equal night." On the autumnal (and the spring) equinox, day and night are roughly 12 hours long in most of the world.
