Summer's reign comes to an end on Thursday, even if the weather doesn't quite feel that way.
The autumn equinox arrives at 10:21 a.m. ET on Sept. 22, marking the official beginning of fall in the Northern Hemisphere, according to the Old Farmer's Almanac.
Like the spring equinox in March, the fall equinox marks an astronomical turning point of the seasons.
People can watch a livestream equinox show starting at 10 a.m. on the O ld Farmer's Almanac website , courtesy of Slooh’s network of observatories.
The word equinox comes from Latin and means “equal night”; night and day are about the same length of time. During the equinox, the sun crosses the “celestial equator” from north to south.
The fall equinox is one of only two days each year when all points on Earth see the sun rise due east and set due west along the horizon, according to National Geographic.
As the hours of daylight declines, the temperatures will begin to drop and the days will start to get shorter.
Soon, the leaves will begin to fall, signaling the start of winter. An old wives tale says if the leaves are slow to fall, be prepared for a cold winter, according to the Old Farmer's Almanac.