March 19 celebrates the arrival of the annual astronomical event, signally season change. With the first equinox of the year, the March counterpart officially marks the end of the winter season, welcoming spring to the Northern Hemisphere. The beginning of daylight saving time has also dragged in the rising daylight hours that will hit an all-time high during the June summer solstice. With the first day of spring 2024, at least for half the world, the astronomical shift has kicked off the vernal equinox. Although the meteorological spring consistently commences on March 1 each year, its astronomical counterpart doesn’t hit the calendar on a fixed date. On the contrary, the Southern Hemisphere is enjoying the first fall season day today.
2024 Vernal Equinox time: According to the National Weather Service, today’s spring equinox for the Northern Hemisphere is scheduled to take over on Tuesday, March 19, at 11:06 pm EDT.
What is the Vernal Equinox?
The NWS defines the word ‘equinox’ as a derivation from two Latin words – ‘aequus’ (equal) and ‘nox’ (night). Twice a year, the Earth’s axis is titled at an angle that makes it neither facing toward the sun nor away from it (Earth’s axis and orbit lining up). The astronomical phenomenon results in “nearly” equal amounts of light and darkness encompassing all latitudes. With these equinoxes occurring only two times a year, the sun is directly overhead at noon at the equator.
Despite the sun’s actual position below the horizon, sunlight’s refraction causes it to appear above it, resulting in nearly equal hours of day and night. The higher altitudes (from the equator) experience longer days because the sun takes longer to rise and set. Consequently, even days before and after the equinox, the day length exceeds about 12 hours and six and half minutes at the equator (with the minutes varying at 30-60 degrees latitude).
Thus, daylight saving time began on Sunday, March 10, bringing more daylight in the evening hours.
The Northern Hemisphere’s fall or autumnal equinox will likely occur between September 21 and 24.
Equinox vs Solstice: What’s the difference?
Unlike how the Earth’s axis is positioned during the equinox, the summer solstice happens when the tilt toward or from the sun is maximum. The summer solstice occurs when the sun is directly over the Tropic of Cancer (23.5 degrees north of the equator). All places north of the Tropic of Cancer witness the sun at its highest point, making way for the year’s longest day. As for the winter solstice, the shortest day comes when the Northern Hemisphere sees the sun directly over the Tropic of Capricorn (23.5 degrees south of the equator).
