The Autumnal Equinox

Fall begins at 3:50 AM on September 23rd.
Posted at 9:52 PM, Sep 22, 2019
and last updated 2019-09-22 21:54:58-04

Happy fall, y'all! Fall will officially begin at 3:50 AM Monday when the Sun's rays are directly over the Equator.

The Autumnal Equinox is the halfway point between the longest and shortest days of the year. The word "equinox" comes from the Latin word meaning "equal night." If you are at the Equator there is a perfect balance of daylight and darkness twice a year. Elsewhere not as equal. In Lexington, sunrise is at 7:26 AM and sunset is 7:33 PM, giving us 12 hours and 7 minutes of daylight. On the equinoxes the sun will rise due east and set due west along the horizon.

We have been gradually losing daylight since the Summer Solstice. The greatest loss in daylight for the mid-latitudes of the North Hemisphere occurs around the Autumnal Equinox in September, and the greatest gains occur after the Vernal Equinox in March. Lexington will lose 2 minutes and 25 seconds of daylight per day. The change in daylight is less dramatic closer to the Equator than the higher latitudes. By the Winter Solstice on December 21st we will be left with around 9 and a half hours of daylight.

Even though autumn is upon us, fall-like weather may take some time to arrive. A hot and dry pattern is expected to persist. The NOAA Climate Prediction Center outlook gives a good chunk of the eastern 2/3rds of the US a 90% chance of seeing above-normal temperatures, including Kentucky, over the next 6 to 10 days. While the overall pattern remains unseasonably warm, there will be brief dose of cooler temperatures. One will follow tomorrow's small shower chance.