JACKSON, Wyo. — Goodbye, summer! It was fun while it lasted.
The autumnal equinox will occur at 12:19 p.m. on Monday, Sept. 22, according to the Old Farmer’s Almanac. This marks the first astronomical day of fall in the northern hemisphere and the first day of spring in the southern hemisphere.
An equinox describes the moment the sun’s center crosses the celestial equator — earth’s imaginary extension of the equator line into space, per the almanac. When the sun crosses the equator going from north to south, this marks the autumnal equinox in the northern hemisphere; when it crosses from south to north, this marks the vernal equinox.
Across the world, this happens at the exact same time, but the hour and day differ depending on the time zone, so the equinox might fall on Sept. 22 or Sept. 23 depending on location.
After the equinox, days become shorter than nights because the sun continues to rise later and nightfall arrives earlier, until the winter solstice. The arc of the sun will slowly creep south, the leaves will begin to change and the temperatures will begin to dip.
Have you taken a beautiful photo of fall foliage in the Jackson area? Email it to tips@buckrail.com for the chance to be featured in an upcoming SNAPPED.
