WINTER SOLSTICE 2025: THE FIRST DAY OF ASTRONOMICAL WINTER – 21/12/2025 - HAPPY WINTER SOLSTICE EVERYBODY! <3
Winter solstice marks the first day of astronomical winter. There are two different calendars that are used to denote seasonal periods (meteorological and astronomical), and it can get a little confusing. Whilst meteorological seasons are based on the annual temperature cycle and climatological patterns observed on Earth (meteorological winter starts on the 1st December), astronomical seasons are based on the position of Earth in relation to the Sun. During the day of the winter solstice, in the Northern Hemisphere we experience the fewest hours of daylight and the sun’s arc or path will appear lower in the sky than at any other time of year.
Whilst those of us in the Northern Hemisphere experience Winter solstice, those in the Southern Hemisphere are experiencing the Summer solstice. This is all thanks to Earth’s tilted axis, so whilst one half of Earth is tilted as far away from the Sun as possible, the other half is pointed as close to it as possible. The Summer and Winter solstices occur when the sun reaches its highest or lowest point relative to the celestial equator.
Around the time of the Winter solstice, we are more likely to experience colder temperatures. The recent full “cold moon” is so called for good reason.
EARTHS TILT – NORTHERN/SOUTHERN HEMISPHERES
The winter solstice occurs when one of Earth's poles has its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern and Southern).
One important thing to consider when hoping to understand solstices better is that whilst those of us in the Northern Hemisphere experience Winter solstice, those in the Southern Hemisphere are experiencing the Summer solstice.
The reason for this is that due to the Earths tilt (of 23.5 degrees) in relation to its orbital path around the Sun, the Northern and Southern hemispheres experience different amounts of sunlight, with one hemisphere experiencing more sunlight than the other due to it tilting towards the Sun. Whilst the other hemisphere experiences less daylight due to it tilting away from the Sun.
Whilst one half of Earth is tilted as far away from the Sun as possible, the other half is pointed as close to it as possible.
Another way to describe the Summer and Winter solstices is when the Sun reaches its highest or lowest point relative to the celestial equator. During the days around the Summer solstice, the Sun’s arc or path will appear higher in the sky than any other time of year. During winter, the Sun’s arc across the sky will appear lower than any other time of year.
WHY IS THE EARTH TILTED?
Most of us know that the Earth is tilted, but why is this? The most agreed upon theory to explain why the Earth is tilted in relation to its orbit, is that around 4.5 billion years ago (very close to the start of our Solar System) a large planetoid named “Theia” collided with the Earth. It is thought that this collision is responsible for the tilt of the Earth, and it is also thought that this event was responsible for the creation of the Moon!
MIDNIGHT SUN / ENDLESS NIGHT
The length of daylight in each hemisphere is not as cut and dry as a North/South hemisphere suggests either. Depending on how far North or South you are located, you will experience more or less sunlight throughout a day. During the December Solstice those further South will experience a longer day and more sunlight, whereas those further North will experience a longer night and less sunlight, and for those within the Antarctic or Arctic Circles the days can be so long or short that they experience endless sunlight or no sunlight at all!
During the December Solstice –
- The South Pole receives 24 hours of daylight, this is known as the “Midnight Sun”. In fact, the South Pole will receive 24 hours of sunlight for 6 months of the year between the September and March Equinoxes.
- The Antarctic Circle receives 24 hours of daylight and also experiences the “Midnight Sun”.
- The Tropic of Capricorn receives roughly 13 hours 35 minutes sunlight, and at noon the Sun will be directly overhead at the zenith.
- The Equator receives 12 hours of sunlight and this does not change throughout the year.
- The Tropic of Cancer receives roughly 10 hours 41 minutes of sunlight.
- The Arctic Circle receives only a hint of sunlight at noon.
- The North Pole has no sunlight and remains without sunlight for 6 months between the September and March equinoxes.
During the June solstice the above is reversed, and the Northern Hemisphere enjoys Summer and the Southern Hemisphere enjoys Winter.
WHEN IS DECEMBER/WINTER SOLSTICE?
We often think of the Winter solstice as an event that spans an entire calendar day, but the solstice actually lasts only a moment. Specifically, it’s the exact moment when our hemisphere is tilted as far away from the Sun as it can be. This year, the Winter Solstice occurs on June 21st at roughly 15:03 GMT.
SOLSTICES AND SEASONS ON OTHER PLANETS
Earth is not the only planet to experience solstices. Any planet that has an axial tilt experiences solstices as well as Earth. Scientists use these solstices to mark the seasons on other planets.
FUN ACTIVITY!
How can we observe the effects of solstice ourselves? On the day of the solstice, stand outside at noon and look at your shadow. It’s the longest shadow that you’ll cast all year! You can see this effect at any date near the solstice too. Do this again on the day of the summer solstice, and you’ll cast a short or no shadow.
CULTURAL SIGNIFICANCE
The winter solstice holds great significance across a variety of cultures, as it signals the changing of the seasons.
The solstice has been celebrated since ancient times by many cultures around our planet. From the Roman feast of Saturnalia to the pre-Christian festival of Norse jól or Juul observed in Scandinavia, there are many ways our ancestors honoured the first day of winter.
In some cultures, the solstice traditionally marked the midway point of the season rather than the start of it, which explains why holidays such as Midsummer Day are celebrated around the first day of summer. The Ancient Celts and Pagans, based their entire calendar around the solstices and equinoxes, marking the Quarter Days, with the mid-points called Cross-Quarter Days.
Some even marked the solstice using huge stone structures, like Newgrange in Ireland. Another famous ancient marker is Stonehenge in England. Due to the alignment of the stones, experts acknowledge that the design appears to correspond with the solstices. One theory is that the area was used as a temple to worship the Sun and/or as a type of astronomical observatory.
ASTROLOGICAL SIGNIFICANCE
For many, the solstices and equinoxes hold great astrological significance, marking the beginning of a new season and each corresponding to one of the four cardinal signs of the zodiac, also known as the cardinal axis. This axis is extremely important in astrology because it is where we find the powerful angles in something called a birth chart. These angles are points of energy manifestation that are thought to effect or even trigger major life events and are associated with qualities of initiative.
The Winter Solstice in particular coincides with the start of the Cardinal zodiac sign Capricorn. From a soul perspective, the Winter Solstice is said to be about celebrating the rebirth of life in all forms. That from here on out, the days will get longer and the Sun will shine brighter, that hope is renewed. Whether it’s an equinox or solstice, it’s about celebrating the start of something new. Each season having it’s own specific and unique job that we rely on. The equinox and solstice points are seen as sacred markers in time that help us connect the dots to the mystery behind the Earth’s never ending circle of life.
WHAT DOES WINTER MEAN TO YOU?
Winter inspires both joy and woe. Some people can’t wait for the cooler winter weather, the snow, the frost, curling up by a fire, the holiday spirit, the long starry nights etc. Personally, I feel a peaceful sort of silence when you walk through the dark starlit woods and by oceans and lakes.
Other people dislike the colder temperatures, snow storms, the wild weather etc and may rejoice that from here on in we will experience more and more daylight as each day passes.
For many astronomers, we will miss the long, dark, starry nights. However, we do have these long, dark nights for some time yet!
Whatever way you view or choose to celebrate the winter solstice, we wish you a cosy, magical, safe, and beautiful winter season!
Clear Skies! 💖