On Earth, there are two equinoxes every year: one around March 21 and another around September 22. Sometimes, the equinoxes are nicknamed the “ vernal equinox ” (spring equinox) and the “ autumnal equinox ” (fall equinox), although these have different dates in the Northern and Southern Hemispheres.
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On Earth, there are two equinoxes every year: one around March 21 and another around September 22. Sometimes, the equinoxes are nicknamed the “vernal equinox” (spring equinox) and the “autumnal equinox” (fall equinox), although these have different dates in the Northern and Southern Hemispheres.
Well that's simple! The equinoxes are when the Sun is right over the Equator, in between the two Tropics. They occur around March 21st and September 23rd and mark the beginning of spring or autumn. We call the beginning of spring the vernal equinox, while the beginning of autumn is, conveniently, the autumnal equinox.
The Equinox (Vernal & Autumnal) There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a "nearly" equal amount of daylight and darkness at all latitudes. These events are referred to as Equinoxes.
On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September. More precisely, an equinox is traditionally defined as the time when the plane of Earth's equator passes through the geometric center of the Sun's disk.
(In the Southern Hemisphere the seasons are reversed.) The equinoxes happen in March (about March 21) and September (about September 23). These are the days when the Sun is exactly above the Equator, which makes day and night of equal length.
Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by reference to the solstices and the equinoxes. The term solstice can also be used in a broader sense, as the day when this occurs.
Equinoxes occur when the axis of rotation of the earth (i.e. the line form the N to S poles) is exactly parallel to the direction of motion of the earth around the sun. This happens on just two days of the year, the spring and autumn equinoxes.
The Earth-in-space view We have an equinox twice a year – spring and fall – when the tilt of the Earth's axis and Earth's orbit around the sun combine in such a way that the axis is inclined neither away from nor toward the sun.
Equinox is the position of the Earth on 21st March and 23rd September. Both the hemispheres experience equal days and nights. - On 21st March in the Northern hemisphere, this position is spring equinox. Autumn equinox is in the Southern hemisphere.
On dates 21st March and September 23rd of the year, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun. Hence, the whole earth experiences equal days and equal nights. This is known as an equinox.
The Equinoxes and the Seasons The March and September equinoxes mark the beginning of the spring and autumn seasons on Earth, according to one definition. The equinox in September is the start of fall in the Northern Hemisphere and the beginning of spring south of the equator.
Time of Equinoxes and SolsticesYearEventDate2021Midwinter SolsticeDecember 21, 2021, 7:59 AM2022Spring EquinoxMarch 20, 2022, 8:33 AM2022Midsummer SolsticeJune 21, 2022, 2:13 AM2022Autumn EquinoxSeptember 22, 2022, 6:04 PM36 more rows