Yr’s quickest sunsets and sunrises
The September equinox will arrive Saturday (September 23, 2023) at 6:50 UTC. And right here’s a little-known equinox phenomenon: the sun units quicker across the time of an equinox. The quickest sunsets (and sunrises) happen at or close to the equinoxes. However, the slowest sunsets (and sunrises) happen at or close to the solstices. It’s true whether or not you reside within the Northern or Southern Hemisphere.
And, by the way in which, after we say sundown right here, we’re speaking concerning the precise variety of minutes it takes for the physique of the sun to sink under the western horizon.
Why does the sun set so shortly across the equinoxes? It’s as a result of, at each equinox, the sun rises due east and units due west. So, which means – on the day of an equinox – the setting sun hits the horizon at its steepest doable angle.
Yr’s slowest sunsets and sunrises
In the meantime, at a solstice, the sun is setting farthest north or farthest south of due west. And, the farther the sun units from due west alongside the horizon, the shallower the angle of the setting sun. So which means an extended period for sundown on the solstices.
Additionally, the sundown period varies by latitude. Farther north or south on the Earth’s globe, the period of sundown lasts longer. Nearer to the equator, the period is shorter. However let’s simply take into account one latitude, 40 degrees north, the latitude of Denver or Philadelphia in america; elements of Spain; and Beijing, China.
At that latitude, on the day of equinox, the sun units in about 2 3/4 minutes.
However, the solstice sun units in roughly 3 1/4 minutes at 40 levels latitude.
Backside line: The quickest sunsets of the yr are occurring now, across the time of the September equinox.
All you need to know about the September equinox
Are day and night equal on the equinox?
