Here is more explanation about how astronomers and meteorologists define seasons differently: Subtract 3 hours for Pacific time, 2 hours for Mountain time, 1 hour for Central time, and so on.įirst Day of Spring 2023: The Spring Equinox Note: The dates above correspond to the start of the listed seasons in the Northern Hemisphere. The First Days of the Seasons 2023 Seasons The meteorological start date is based on our 12-month civil calendar as well as the annual temperature cycle.The astronomical start date is based on the position of the Sun in relation to the Earth.It sounds complicated, but trust us, it’s not! Each season has both an astronomical start and a meteorological start.
The dates when the seasons begin and end vary depending on whom you ask. Plus, learn more about what the solstices and equinoxes mark (and guess which of the four seasons is shortest!). The subsolar point crosses the equator moving northward at the March equinox and southward at the September equinox.What are the solstice and equinox dates for 2023? (Yes, the dates can change from year to year!) Here are the first days of the four seasons: summer, fall, winter, and spring. the Sun is exactly overhead at a point on the equatorial line. Then the northern and southern hemispheres are equally illuminated.Įquinoxes are the only times when the subsolar point is on the equator, i.e. The equinoxes are the only times when the solar terminator (the dividing line between night and day) is perpendicular to the equator. The March equinox marks the moment the Sun crosses the celestial equator – the imaginary line in the sky above the Earth’s equator – from south to north and vice versa in September. The word equilux is used to mean a day in which the durations of light and darkness are equal to distinguish the day from an equinox. They are not exactly equal because the angular size of the sun and atmospheric refraction.
On an equinox, the Sun shines directly on the equator and the length of day and night is nearly equal – but not quite. credit: NASA/SVS & NASA’s Earth Observatory Not Entirely Equal Day & Night
On the March equinox, the terminator is a north-south line once again. The word Equilux is used to mean a day on which the periods of daylight and night are equal. Solstices also mark the change from fall to winter or spring to summer. On the December solstice, the sun reaches its highest point in the sky for an observer at the South Pole. On the June solstice, the sun reaches its highest point in the sky for an observer at the North Pole. The astronomical event, known as an equinox, occurs twice each year, the March equinox (usually March 20) and the September equinox (usually September 22), when the plane of Earth’s equator passes through the center of the sun. If you want to jump right in, go to about 1:40. It’s the Autumnal (Fall) equinox for the Southern Hemisphere!īefore we go into the details, let’s hear from an astrophysicist. PDT on September 22, 2022) It’s the Vernal (Spring) equinox for the Northern Hemisphere! The 2022 March Equinox happens on Maat 15:33 UTC (11:33 am EDT ĪLRIGHT! It’s a change of season! The next Equinox occurs on Septemat 1:03 UTC (9:03 p.m.
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