For that hemisphere, the winter solstice is the day with the shortest period of daylight and longest night of the year, and when the Sun is at its lowest daily maximum elevation in the sky.

There is evidence that the winter solstice was deemed an important moment of the annual cycle for some cultures as far back as the Neolithic (New Stone Age).

[10][11][12] Some important Neolithic and early Bronze Age archaeological sites in Europe are associated with the winter solstice, such as Stonehenge in England and Newgrange in Ireland.

It is significant that at Stonehenge the Great Trilithon was oriented outwards from the middle of the monument, i.e. its smooth flat face was turned towards the midwinter sunset.

[14] Plutarch wrote in the Moralia (first century AD) that the Egyptians believed the goddess Isis gave birth to Harpocrates (Horus the Child) at the winter solstice.

At the temple of Kore (the Koreion) in Alexandria, an all-night vigil was held, and at dawn an idol of the child god was brought out of an underground chapel.

[23] In AD 274, the emperor Aurelian made this the date of the festival Dies Natalis Solis Invicti, the birthday of Sol Invictus or the 'Invincible Sun'.

[20][24] Gary Forsythe, Professor of Ancient History, says "This celebration would have formed a welcome addition to the seven-day period of the Saturnalia (December 17–23), Rome's most joyous holiday season since Republican times, characterized by parties, banquets, and exchanges of gifts".

[24][20][26] According to C. Philipp E. Nothaft, a professor at Trinity College Dublin, a historically Protestant University, though this "is nowadays used as the default explanation for the choice of 25 December as Christ's birthday, few advocates of this theory seem to be aware of how paltry the available evidence actually is".

[27] Discussing the Heruli, the Greek historian Procopius wrote in the sixth century that the people of Scandinavia (which he calls Thule) held their greatest festival shortly after the winter solstice, to celebrate the return of daylight.

The Heimskringla, written in the 13th century by the Icelander Snorri Sturluson, describes a Yule feast hosted by the Norwegian king Haakon the Good (c. 920–961).

Albanologist Johann Georg von Hahn (1811 – 1869) reported that Christian clergy, during his time and before, have vigorously fought the pagan rites that were practiced by Albanians to celebrate this festivity, but without success.

[36] The old rites of this festivity were accompanied by collective fires (zjarre) based on the house, kinship or neighborhood, a practice performed in order to give strength to the Sun according to the old beliefs.

The rites related to the cult of vegetation, which expressed the desire for increased production in agriculture and animal husbandry, were accompanied by animal sacrifices to the fire, lighting pine trees at night, luck divination tests with crackling in the fire or with coins in ritual bread, making and consuming ritual foods, performing various magical ritualistic actions in livestock, fields, vineyards and orchards, and so on.

In Japan, in order not to catch cold in the winter, there is a custom to soak oneself in a yuzu hot bath (Japanese: 柚子湯 = Yuzuyu).

An Aggadic legend found in tractate Avodah Zarah 8a puts forth the talmudic hypothesis that Adam first established the tradition of fasting before the winter solstice, and rejoicing afterward, which festival later developed into the Roman Saturnalia and Kalendae.