Not usually. This is because of a weird delay called seasonal lag. Is the shortest day of the year also the coldest? 'What matters is not sunset and sunrise, but the difference between them is shortest ,' Professor Bedding said. This means that the earliest sunset will occur before the winter solstice, while the latest sunrise will happen after it's passed. Sunrises and sunsets also gradually become later after the winter solstice. This means that solar noon - the time at which the Sun reaches the highest point in the sky - doesn't occur at the moment your clock hits midday.Īround the winter solstice, solar noon occurs a few minutes later than the day before. Similarly, the length of a solar day isn't precisely 24 hours long. 'A year isn't exactly an even number of days,' he said.Īnd what about late sunrises and early sunsets? The Earth takes about 365 and a quarter days to whip around the Sun, which is why we have leap years, Professor Bedding said. While our trusty calendars help us map out the year, they don't sync up perfectly with the Sun's movements. Why doesn't it occur on the same day each year? The spring and autumn equinoxes occur when the Sun appears directly above the equator, leading to days and nights being roughly equal in length.

In the southern hemisphere, this falls sometime between June 20-22 (June 21 this year), while in the northern hemisphere it usually occurs on either December 21 or 22. The winter solstice marks the point at which the southern or northern hemisphere is tilted furthest away from the Sun. 'During winter, our part of the Earth is tilted away from the Sun and therefore isn't above the horizon for as long every day,' said Tim Bedding, an astronomer at the University of Sydney. Welcome to summer!Īt the same time, the other side of the world is tilted away from the Sun, leading to chilly temperatures and longer nights. This results in warm weather and short nights. On top of that, the Earth doesn't travel around the Sun in a perfect circle, but in a football-shaped ellipse.Īs the Earth completes one lap around the Sun each year, different parts of the planet are tilted towards our star at different times and get the most direct sunlight. This tilt is what gives us the four seasons: winter, spring, summer, and autumn. Rather than rotating perfectly vertically, our planet is tilted at about 23 degrees. It all comes down to Earth being a little wonky on its axis. So, what's behind this astronomical phenomenon? Why do we have the winter solstice? Next Tuesday, June 21, the southern hemisphere will experience its shortest day and longest night of the year.Īnd as we're plunged into darkness, the northern hemisphere will enjoy the summer solstice, the longest day and shortest night of the year. The days are getting shorter and colder and afternoons spent soaking up the sun are well and truly behind us - especially in the southern states.īut if you think the mornings are dark and gloomy now, wait until we hit the winter solstice.

Winter equinox