Is the Winter Solstice Really the Shortest Day of the Year?

Is the Winter Solstice Really the Shortest Day of the Year?
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We are officially in winter, folks and that means it’s time to prepare for the annual winter solstice.

The solstice is one of those events that comes around every year, but maybe you’re not fully aware of what it actually means. Let’s break it down.

What is the winter solstice?

The solstices and equinoxes are used to signal the change in seasons and are all based on the tilt of the Earth as it travels around the sun.

Basically, when the Earth rotates around the sun it does so while it’s slightly off-centre. That’s why we get different seasons. Here’s how Encyclopaedia Britannica explains it:

The seasons on Earth change because the planet is slightly tilted on its axis as it travels around the Sun. This means different points on Earth receive more or less sunlight at different times of year. If Earth were not tilted, the Sun would always appear to be directly above the Equator, the amount of light a given location receives would be fixed, and there would be no seasons.

So when it comes to the solstices and equinoxes, these mark the occasions the Earth is at its maximum tilt either towards or away from the sun. The summer and winter solstices also occur at opposite times depending on which hemisphere you’re in.

So while we experience the winter solstice this month, those in the northern hemisphere will enjoy the summer solstice.

Is it really the shortest day of the year?

The winter solstice does technically mark the shortest day of the year, but this doesn’t mean there are fewer hours or minutes that make up the day. It also doesn’t mean this is the day when the sun rises at its latest or sets at its earliest.

As Geoscience Australia explains:

Because the path of the Earth around the Sun is an ellipse, not a circle, and because the Earth is off-centre on its axis, these combined phenomena can create up to several minutes difference between solar and mean time. Around the date of summer solstice, these effects make the Sun appear to move slightly slower than expected when measured by a watch or clock.

As a result, the earliest sunrise occurs before the date of the summer solstice, and the latest sunset happens after the summer solstice. For the same reasons, around the winter solstice, the time of sunrise continues to get later in the days after the solstice.

When we refer to the shortest day of the year we’re actually talking about the number of daylight hours. The winter solstice is the day where we’ll see the least amount of daylight in 24 hours, due to the tilt of the Earth.

When is the winter solstice in Australia?

The winter solstice will take place on Monday, June 21, 2021.

As it’s the shortest day of the year we’ll experience roughly 9 hours and 53 minutes of daylight in Sydney, although this varies depending on how far north or south you are. You can check out your city’s daylight hours over at Time and Date.

This is roughly 4 hours and 30 minutes less than the longest day of the year which occurs on the summer solstice in December.

There’s not really much to do on the winter solstice except pack some extra layers. There’s also a neat solstice festival happening in Sydney this year if you want to check that out.

This article has been updated since its original publish date.

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