Winter Begins

Winter Solstice 2019: The First Day of Winter 

Winter officially begins with the Winter Solstice on Saturday, December 21, 2019. This is the astronomical first day of winter in the Northern Hemisphere. Enjoy our winter solstice facts, folklore, FAQs, and more!

When is the Winter Solstice?

The winter solstice is the day with the fewest hours of sunlight in the whole year. In the Northern Hemisphere, it always occurs around December 21 or 22. (In the Southern Hemisphere, the winter solstice occurs around June 20 or 21.)

In 2019, the winter solstice arrives on Saturday, December 21, at 11:19 pm EST. 

What is the Winter Solstice?

The word solstice comes from Latin sol “sun” and sistere “to stand still.” In the Northern Hemisphere, as summer advances to winter, the points on the horizon where the Sun rises and sets advance southward each day; the high point in the Sun’s daily path across the sky, which occurs at local noon, also moves southward each day. At the winter solstice, the Sun’s path has reached its southernmost position. The next day, the path will advance northward. However, a few days before and after the winter solstice, the change is so slight that the Sun’s path seems to stay the same, or stand still. The Sun is directly overhead at “high-noon” on Winter Solstice at the latitude called the Tropic of Capricorn.

Winter FAQs

Question: Why is there such a time lag between the shortest day of the year (shortest amount of daylight hours) and the lowest average daily temperature of the year?

Answer: The day of the winter solstice is the shortest day of the year, meaning the one in which we experience the least amount of daylight in 24 hours; it is also the time when the Sun reaches its southernmost point in the sky. Although this part of Earth is cooling, its great thermal mass still retains some heat from the summer and fall. As the gradual cooling process continues over the next two months, temperatures will continue to fall, and the coldest temperatures will be recorded. The same pattern holds true for the summer solstice in June, as the year’s highest temperatures are recorded later, in July and August (in the Northern Hemisphere).

Question: Was Stonehenge built to celebrate the winter solstice?

Answer: That’s one theory. Stonehenge was constructed in several phases over a period of many centuries. Due to the alignment of the stones, experts acknowledge that the design appears to correspond with the use of the solstices and possibly other solar and lunar astronomical events in some fashion. There are several theories as to why the structure was built, including that the area was used as a temple to worship the Sun; as a royal burial ground; and/or as a type of astronomical observatory. However, because none of these theories has been proven correct as yet, the true reason (or reasons) for Stonehenge’s existence remains a mystery. Read more about Ancient Sites Aligned with the Solstice and Equinox.

Question: Is the solstice the start of winter or the mid-point of winter?

Answer: There is not a black-and-white answer—it depends. We follow what the astronomical calendar tells us. The solstice is the beginning of astronomical winter. (An almanac is defined as a “calendar of the heavens,” so we use the astronomical definition as well.) Astronomical seasons are based on the position of the Earth in relation to the Sun. However, meteorological seasons are based on the annual temperature cycle. It is important for meteorologists to be able to compare climatological statistics for a particular season from one year to the next for agriculture, commerce, and a variety of other purposes. Thus, meteorologists break the seasons down into groupings of three months. Winter includes December, January, and February.

https://www.almanac.com/content/first-day-winter-winter-solstice