When Is The Winter Solstice?
The winter solstice for the Northern Hemisphere occurs on Tuesday, December 21, 2021 at 10:59 a.m. EST.
What Is The Winter Solstice?
It’s the astronomical moment when the Sun reaches the Tropic of Capricorn, we have our shortest day and longest night of the year in the Northern Hemisphere in terms of daylight. Regardless of what the weather is doing outside your window, the solstice marks the official start of winter.
What Does “Solstice” Mean?
The term “solstice” comes from the Latin words sol (Sun) and sistere (to stand still) because, during the solstice, the angle between the Sun’s rays and the plane of the Earth’s equator (called declination) appears to stand still.
So what does that mean, exactly? Upon the winter solstice, the Sun appears at its lowest in the sky, and its noontime elevation seems to stay the same for several days before and after this day. The Sun’s gradual decrease in the sky reverses upon the winter solstice, marking what many cultures believe to be a “rebirth” of the Sun as the hours of daylight become longer.
Essentially, our hours of daylight—the period of time each day between sunrise and sunset—have been growing slightly shorter each day since the summer solstice last June, which is the longest day of the year (at least in terms of light). After December 21, the days will begin to grow longer and will continue to do so until we reach the summer solstice again in June, and begin the whole cycle anew.
While we celebrate the winter solstice, those living in the Southern Hemisphere will be simultaneously marking the arrival of summer. That’s because while our half of the globe is inclined away from the Sun, their half is inclined toward it. Being tilted away from the Sun brings us shorter days and colder temperatures.
Early man kept track of the days by observing the Sun as it “moved” across the sky and cast shadows during the day and at different times of the year. In fact, historians believe Stonehenge in England was erected to keep track of the Sun’s yearly progress.