Today (December 21) is the shortest day of 2016 and marks the official start of winter.
The annual winter solstice occurs on the latest dawn of the year and when the sun sits at its lowest point in the sky.
Today the sun rose in the UK at 8:04am and will set at 3:54pm, giving British citizens just 7 hours and 49 minutes of daylight to enjoy.
The solstice signals an end to the increasingly long and dark winter nights as days get gradually longer until the summer solstice arrives on Wednesday, June 21, 2017.
The date of the winter solstice is different every year, falling at some point between December 20 and 23.
It occurs at the point when the North Pole is tilted exactly 23.5 degrees away from the sun, this happened at at 10.44 am today.
As the northern hemisphere leans away from the sun countries in that part of the world experience longer hours of darkness.
During the winter solstice areas to the north of the Arctic circle are even plunged into 24 hours of night.
According to the Royal Observatory in Greenwich, London, the word 'solstice' comes from the Latin solstitium meaning 'Sun stands still' because the apparent movement of the sun across the sky from north or south stops before it appears to change direction.
The event is a astronomical rather than a meteorological phenomenon, with weather forecasters having marked winter's arrival at the start of December.
A spokesperson for the Met Office said: "The winter solstice marks the start of astronomical winter. Meteorologically, winter begins on the first of December. When charting our weather and climate, the calendar is divided into four equal parts."
The meteorological winter began on December 1, 2016 and will end on February 28, 2017.
Whereas the astronomical winter begins on December 21, 2016 and ends on March 19, 2017.
Tom Kerss, Astronomer at the Royal Observatory Greenwich said: "The cultural significance of the Winter Solstice goes right back to the ancient world.
"It has long been understood that after this moment, hours of daylight gradually begin to lengthen – day pushes back night until the two even out at the Vernal (Spring) Equinox.
"Although it is true that the Winter Solstice coincides with the shortest day of the year in the Northern Hemisphere, there is a discrepancy in the date of earliest sunset owing to the elliptical shape of the Earth’s orbit around the Sun.
"Around the Solstices, the time of true solar noon is shifted, because solar days are not all exactly 24 hours long – this is an average figure across the year.