The arrival of summer and winter always begins with a solstice. The winter solstice has unique characteristics that make it the coldest time of year in the Northern Hemisphere. Many people are not familiar with what the winter solstice is.
For this reason, we are going to dedicate this article to telling you what the winter solstice is, what its characteristics and importance are.
What is the winter solstice
We refer to the solstices as the two points in the sun's annual course when noon coincides with two of Earth's tropical regions: Cancer and Capricorn, thus reaching its maximum declination with respect to the Earth's equator. In other words, the solstice occurs when the sun reaches its highest or lowest apparent altitude in the sky, either +23° 27′ (north) or -23° 27′ (south) of the Earth's equator . To learn more about this phenomenon, you can check out our publications on solstices and equinoxes.
The solstice occurs twice a year: the summer solstice and the winter solstice , marking the beginning of these seasons, the hottest or the coldest depending on the hemisphere. Thus, towards the end of June, the summer solstice occurs in the Northern Hemisphere, while the winter solstice occurs in the Southern Hemisphere, and vice versa, towards the end of December. This phenomenon is related to the apparent movement of the planets.
The word solstice comes from the Latin sol Sistere ("still the sun"), because these days mark the longest (summer) and shortest (winter) periods of the year. For this reason, various ancient cultures paid special attention to these two days, seeing them as the peak of heat or cold, thus associating them with the sun's dominion and its greatest radiance, vitality, and brilliance. During the winter solstice, there is less light, less fertility, and more cold, leading to a greater presence of the spiritual world, often considered the nocturnal realm. In fact, the most popular winter solstice tradition is Christmas. If you'd like to learn more about this topic, check out our interesting facts about the winter solstice.
solstice and equinox
The solstices are the points when the sun is farthest from the equator, producing its respective summer and winter maximums, while the equinoxes are the opposite: days when the plane of the sun coincides most closely with the Earth's equator, thus producing days and nights of approximately equal length. There are also two equinoxes throughout the year, in March (spring) and September (autumn), in the Northern Hemisphere (they are opposite in the Southern Hemisphere). For more information on the differences between these two phases, we invite you to read our article on the summer solstice.
Many traditional human cultures see the equinox as the date of the change from one plane to another, a time of welcome transition between life (spring, greenery) or death (autumn, falling leaves).
Is the winter solstice the first day of the season?
The reason for the solstices and seasons is that the Earth is tilted an average of 23,5 degrees relative to the sun . Therefore, as we orbit our star, the northern and southern hemispheres receive different amounts of sunlight throughout the year.
The part of each hemisphere that is farthest from the sun cools during the year. The winter solstice (December in the north, June in the south) occurs when this tilt is at its most extreme. This astronomical phenomenon occurs on the first day of winter on the calendar, but meteorologists are ahead of us this season. As the winter solstice approaches, climatologists have been watching winter conditions for nearly a month, according to Greg Hammer of NOAA's National Center for Environmental Information.
“Meteorological winters in the Northern Hemisphere always occur in December, January, and February, as these are typically the coldest months of the year. This is based on an annual temperature cycle, not an astronomical basis,” he explained. If you'd like to learn more about this topic, feel free to check out our article on hours of sunlight in winter.
Given the huge impact sunlight has on Earth's climate, why isn't the darkest time of year the coldest? Basically, in the summer, the water and land need time to cool down after all the heat has been absorbed. Therefore, the minimum temperature of the day does not occur until almost a month later.
Meteorological winters are more a reflection of the popular calendar and how most people perceive the seasons. We think of winter as the coldest time, summer as the hottest, and spring and summer as transitional periods. Most of us see the first sunsets a week or two before the winter solstice. That's because the sun and our human clock don't exactly align.
We have divided our days into 24-hour periods, but the Earth does not rotate on its axis with such precision. While there is always an exact 24 hours from one noon to the next, the time between solar noon, the time the sun reaches its highest point in the sky each day, varies. Over time, the time of solar noon varies with the season, as do sunrise and sunset.
In December, solar noon occurs about 30 seconds after the 24-hour cycle is complete . Although we receive the least amount of daylight on the solstice, sunset that day is a few minutes later than earlier in the month.
Closer to the equator, the earliest sunset of the year occurs in November. To see it coincide with the Solstice, you have to go to the North Pole. Seasonal changes in the sun's path across the sky closer to the poles cause sunsets at higher latitudes to be closer to the winter solstice.
Can you see the winter solstice?
You can understand the effects of the winter solstice by observing what happens in the sky and how sunlight changes over time. For observers in the Northern Hemisphere, the sun's arc in the sky has been decreasing and shortening since June. At the Northern Hemisphere's winter solstice, it reaches its lowest point, so low that it appears to rise and set in the same place for several days before and after the solstice.
Due to the sun's lower angle, this means that our midday shadows are the longest of the year during the winter solstice.
I hope that with this information you can learn more about the winter solstice and its characteristics.
