winter

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winter

season

Also known as: hiemal period

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Last Updated: May 15, 2025 • Article History

Related Topics:: calendar; polar vortex; volcanic winter; nuclear winter; Why Is Summer Warmer Than Winter?

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Air Transat will offer direct flights from P.E.I. to Cancun next winter • May 15, 2025, 4:16 AM ET (CBC)

winter, coldest season of the year, between autumn and spring; the name comes from an old Germanic word that means “time of water” and refers to the rain and snow of winter in middle and high latitudes. In the Northern Hemisphere it is commonly regarded as extending from the winter solstice (year’s shortest day), December 21 or 22, to the vernal equinox (day and night equal in length), March 20 or 21, and in the Southern Hemisphere from June 21 or 22 to September 22 or 23. The low temperatures associated with winter occur only in middle and high latitudes; in equatorial regions, temperatures are almost uniformly high throughout the year. For physical causes of the seasons, see season.

The concept of winter in European languages is associated with the season of dormancy, particularly in relation to crops; some plants die, leaving their seeds, and others merely cease growth until spring. Many animals also become dormant, especially those that hibernate; numerous insects die.

The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Meg Matthias.

winter solstice

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winter solstice

astronomy

Also known as: hibernal solstice

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Also called:: hibernal solstice

Related Topics:: Wicca; Yule; winter; December; June

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winter solstice, the two moments during the year when the path of the Sun in the sky is farthest south in the Northern Hemisphere (December 21 or 22) and farthest north in the Southern Hemisphere (June 20 or 21). At the winter solstice the Sun travels the shortest path through the sky, and that day therefore has the least daylight and the longest night. (See also solstice.)

When the winter solstice happens in the Northern Hemisphere, the North Pole is tilted about 23.4° (23°27′) away from the Sun. Because the Sun’s rays are shifted southward from the Equator by the same amount, the vertical noon rays are directly overhead at the Tropic of Capricorn (23°27′ S). Six months later the South Pole is inclined about 23.4° away from the Sun. On this day of the winter solstice in the Southern Hemisphere, the Sun’s vertical overhead rays progress to their northernmost position, the Tropic of Cancer (23°27′ N).

According to the astronomical definition of the seasons, the winter solstice also marks the beginning of the season of winter, which lasts until the vernal equinox (March 20 or 21 in the Northern Hemisphere, or September 22 or 23 in the Southern Hemisphere). After the solstice, the days get longer, and the day has thus been celebrated in many cultures as a time of rebirth.

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What is the difference between solstices and equinoxes?
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Why do some cultures have holidays around the winter solstice time?

The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Meg Matthias.