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ABC News
an hour ago
- Health
- ABC News
The winter solstice in Australia is today. Here's how the shorter days of winter can affect your sleep patterns
Australia will have its "shortest day of the year" today as the southern hemisphere experiences the winter solstice. Where you are in Australia will determine just how much daylight you will get. The shortest day of the year can also impact your sleep. Here's what that means. Saturday, June 21. According to the exact moment the southern hemisphere is at its furthest tilt from the Sun will be at 12:42pm AEST. While the winter solstice is referred to as the shortest day and longest night of the year, it actually just means it is the day with the least amount of daylight hours. That's because it's when the southern hemisphere is at its furthest tilt away from the Sun, meaning we get less sunlight. At the same time, the northern hemisphere will be experiencing the summer solstice, which is the longest day of the year. This happens because the Earth tilts at about 23 degrees, meaning that when one side is closest to the Sun, the other side is furthest away. As the Earth does a lap around the Sun each year, different parts of the planet get more sunlight than others. After Saturday, each day's total sunlight hours will get a fraction longer than the previous day until we reach the summer solstice on December 22. According to the astronomical definition of the seasons, the winter solstice in some places marks the beginning of winter. But in Australia, where only meteorological seasons are observed, this is not the case. That's why the beginning of winter is June 1 here. In some cultures, the winter solstice is celebrated as a time of rebirth because the days get longer. Because it is getting dark so early and the days are shorter, some people may experience changes in their sleep schedule and quality. Elise McGlashan, from the University of Melbourne's John Trinder Sleep Laboratory, says shorter days and longer nights mean less sunlight, which can change circadian rhythms. The circadian rhythm is the internal body clock that regulates sleep. "Those changes in sleep can also be accompanied by changes in timings and function of our internal clock and the function of our clock is mainly driven by environmental light exposure," she says. "In summer, we know the sun might be up until it's close to someone's bedtime, and part of the reason people are sleeping a little longer is they aren't getting those light cues when they're trying to wind down. "But during winter, there is less light and more time to wind down." When there is less light exposure, the body produces more melatonin — a hormone that makes people feel sleepy — and less serotonin, which can lower mood and energy, leading to feeling tired or sluggish. As the sun comes up later, it may be tempting to sleep longer but oversleeping can also impact health. Dr McGlashan recommends getting outside for some sunlight during the day and letting sunlight into your bedroom in the mornings if possible. "Our rhythms need bright days and dark nights," she says. "It can be hard to motivate ourselves to go outside in winter, particularly in a really chilly location, but even on those overcast days, the light outside is going to be brighter than indoor lighting. "It's still really helpful for your body clock and sleep to get outdoor lighting every day."
Daily Mail
2 days ago
- Climate
- Daily Mail
Australia braces for the darkest week of the year during the winter solstice
Millions of Australians will shiver through the darkest week of the year as the annual winter solstice approaches this weekend. The southern hemisphere's winter solstice on Saturday, June 21, marks the shortest day and longest night of the year based on the time between sunrise and sunset. The three days before and after the solstice will contribute to a seven-day period with the least amount of daylight for the year. Hobart will have the shortest day, while Darwin will have the longest. The sun will rise at 7.42am in the island state and set at 4.43pm, while in Darwin, the sun will come up at 3.36am and set at 6pm. Darwin's day length will be 11 hours and 24 minutes compare to just nine hours and one minute in Hobart. Each hemisphere has a winter solstice, spaced six months apart. The southern hemisphere marks the winter solstice when the sun appears to be at the lowest point in the sky when viewed from the equator. The days will slowly begin to get longer and the nights shorter in the next six months until the summer solstice arrives in Australia between December 21 and 22. The solstice is caused by Earth's tilt on its axis and its orbital motion around the sun. The Earth is tilted on its axis by 23.5degrees with the tilt allowing northern and southern hemispheres to trade places in receiving the sun's light and warmth. It's the Earth's tilt, not its distance from the sun, that causes winter and summer.
