When is the shortest day of the year? The exact date of Winter Solstice 2025

The winter solstice, a phenomenon revered by ancient civilisations, continues to hold profound significance today as it heralds the official start of winter.

This annual event marks the shortest day of the year, characterised by the fewest hours of daylight, and conversely, the longest night. It is also the precise moment when the sun reaches its lowest daily maximum elevation in the sky.

The term "solstice" itself is rooted in Latin, combining "sol," meaning sun, with "sistere," which translates to "to come to a stop" or "make stand."

While the Southern Hemisphere embraces the onset of summer, those residing north of the equator will observe the opposite – the inaugural day of winter. This year, the celestial event is set to occur on Sunday 21 December at 3:03 pm.

Depending on where you are in the UK, the exact length of the day will differ. In London, there will be 7 hours 49 minutes and 42 seconds of daylight. That means it is 8 hours and 49 minutes shorter than the June solstice.

While that means that the day is likely to be dark and dreary, the good news is that it also means that the days will get progressively longer, with more hours of daylight until the climax of the summer solstice.

The variation happens because the Earth orbits the sun at an angle of 23.4 degrees on its axis, according to the Royal Museums of Greenwich.

During the warmer periods, the North Pole is tilted towards the sun in the northern hemisphere, meaning longer daylight hours, while the southern hemisphere experiences the opposite. During winter the situation is reversed as the North Pole tilts away from the sun for the northern hemisphere.

Arriving on the same day across the globe, a solstice occurs when the sun reaches its lowest or highest point in the sky during the year as a result of the Earth’s axis tilting to or away from the sun.

For the Southern Hemisphere, it’s the opposite case, as 21 December marks the one day of the year with the longest period of sunlight.

Historically, the winter solstice has been of great importance to many cultures, such as Ancient Egypt and Ancient Rome, often as a marker for the passing seasons, and a possible time of rebirth.

In northern Europe, from the Faroe Islands to Estonia, Germanic peoples have long celebrated the event, which became known as Yule.

While Yule dates back to the Norse people, who celebrated the sun’s rebirth for 12 days, it was also celebrated by Anglo-Saxon pagans.

According to Pliny the Elder, in Britain, druid priests would mark the important date by gathering mistletoe and sacrificing bulls – which was also likely a practical measure to limit the number of mouths to feed during months of famine.