When is the shortest day of the year 2020? Date of the winter solstice and how many hours of daylight there are
The shortest day of the year is fast approaching.
Daylight hours have been dwindling for months and – with the countdown to Christmas well and truly on – winter is coming.
But, before the annual tucking into a turkey, there is a celebration to mark the shortest day of the year – otherwise known as the winter solstice.
Here’s when there will be the fewest daylight hours within a 24-hour period in the northern hemisphere in 2020.
When is the shortest day of the year?
This year’s winter solstice - the point where the sun is lowest in the sky - will take place on Monday 21 December.
It always happens in the northern hemisphere in December, though its timing varies slightly with every passing year.
This is because there are 365.25 days in our calendar year, or how long it takes for the earth to orbit the sun, meaning the exact time the sun is lowest in the sky shifts approximately six hours each year.
We also skip a day every four years - a leap year - which adjusts the timings. Last year, for example, the shortest day was on 22 December, but because 2020 is a leap year, the date of winter solstice shifts back 24 hours.
How long is this year’s winter solstice?
The number of daylight hours on the shortest day amounts to 7 hours, 49 minutes and 42 seconds - some 8 hours, 48 minutes and 38 seconds shorter than the summer solstice, when daylight hours are at a maximum.
According to the Royal Museum Greenwich website, the actual moment of the solstice will take place around 10.02am on 21 December in the UK.
While there have been fewer daylight hours since the summer solstice, the winter solstice marks a gradual increase in the length of days and the shortening of the nights.
Why do we have the shortest day and the longest day?
The earth’s axis is tilted 23.4 degrees as it rotates the sun which means its pole points are either angled towards or away from the sun.
The shortest day of the year in the northern hemisphere marks the time when the north pole is pointing away from the sun. It’s also the reason why it is much colder in the winter than in the summer, with much less exposure to sunlight than the southern hemisphere during this time.
The opposite occurs for the northern hemisphere’s longest day, which occurred on Saturday 20 June this year.
What does solstice mean?
Solstice comes from the Latin word solstitium which means ‘sun stands still’ “because the apparent movement of the sun’s path north or south stops before changing direction,” states rmg.co.uk.
The solstice is an important time of the year for many cultures historically, while people still flock to Stonehenge to celebrate the winter and summer solstices and get a glimpse of the sun’s rays beaming through the ancient stones.