In the northern hemisphere, winter solstice is the shortest day of the year. The exact moment of the solstice happens between Dec. 21 and Dec. 22, depending on the particular year’s calendar. During the winter solstice, the northern half of the Earth is tilted away from the sun, states the National Earth Science Teachers Association. At the winter solstice, the sun appears lower in the sky for residents of the northern hemisphere—as it has been “sinking” since the summer solstice.
Less sunlight, more winter. The winter solstice marks the start of winter in the northern hemisphere, which means this area of the planet is receiving less direct sunlight than the southern hemisphere. When the northern hemisphere experiences winter, the southern hemisphere experiences summer. Likewise, when the northern hemisphere basks in warmth of summer, the southern hemisphere experiences the cooler temperatures of winter.
Longer days. After the winter solstice, the days in the northern hemisphere will begin to get longer. This continues until the summer solstice, which marks the longest day of the year in the northern hemisphere. The lengthening of days appears imperceptible. According to the Sydney Observatory in Australia, “The name solstice comes from this fact as it means the Sun stands still.” However, their lengthening can be charted by noting the exact time of sunrise and sunset. In Australia, part of the southern hemisphere, the winter solstice occurs in and around June 21 (the summer solstice in the northern hemisphere).
Winter solstice celebrations. Throughout history, the winter solstice has been a time of celebration in many cultures. In the northern hemisphere, the ancient Roman festival of Saturnalia, honoring the God Saturn was celebrated during winter solstice. Saturnalia lasted about a week. The Druids also celebrated winter solstice with the festival of Saturnalia. Across the Atlantic, various Native American tribes celebrated winter solstice with festivals and gatherings.
Ancient Celtic winter solstice. On the winter solstice in Newgrange, County Louth, Ireland, an ancient Celtic tomb adorned with Celtic artwork illuminates for about 20 minutes on the sunset of the shortest day of the year. The Newgrange tomb is older than Stonehenge and the Egyptian pyramids. It was discovered in 1969 and is thought to have been built about 3200 BC.