We all know the feeling: some nights, you drift off as soon as your head hits the pillow, while others, you’re left tossing and turning, counting sheep (or perhaps kangaroos) until the wee hours.
But have you ever wondered why your sleep seems to ebb and flow with the seasons, or why you’re more likely to hit the snooze button on a Sunday morning?
Sleep isn’t just about good habits or a comfy mattress. A fascinating new global study has revealed how much our environment—from the tilt of the Earth to the clock—shapes our nightly slumber.
According to lead author Hannah Scott from Flinders University, ‘Sleep patterns aren’t just about habits—they’re deeply connected to the environment around us.’
The study, which analysed a staggering 73 million night sleep data from 116,000 adults worldwide, found that everything from daylight hours to temperature, and even our weekly routines, can surprisingly strongly influence the quality and quantity of our sleep.
Summer vs. Winter
Ever noticed you’re a bit more bleary-eyed in summer? You’re not imagining it. The research found that people sleep, on average, 15 to 20 minutes less per night during the summer months, and then catch up with an extra 20 to 35 minutes in winter.
That might not sound like much, but over weeks and months, it adds up and can impact your well-being.
Why the difference? Longer daylight hours in summer can delay the release of melatonin, the hormone that helps us feel sleepy.
Warmer nights can also make it harder to fall and stay asleep. In winter, the longer nights and cooler temperatures create a more sleep-friendly environment, encouraging us to snuggle up and get those extra Zs.
Weekends
It’s not just the seasons that play havoc with our sleep. The study also found that most of us go to bed at least 30 minutes later on weekends.
Whether catching up with friends, watching a late-night movie, or enjoying a well-earned lie-in, our social schedules can throw our body clocks out of whack.
During the holiday period from December to January, sleep patterns became even more irregular, a reminder that festive fun can come at the cost of a good night’s rest.
Location, Location, Location
You might not have considered that your postcode could be affecting your sleep. The further you live from the equator, the more your sleep patterns will likely shift with the seasons.
So, if you’re in Melbourne or Hobart, you might notice bigger changes in your sleep between summer and winter than your friends up in Queensland or the Northern Territory.
The hidden costs of irregular sleep
While a late night here or there might not seem like a big deal, the study warns that ‘irregular sleep’ can negatively impact your physical and mental health.
Poor sleep has been linked to everything from heart disease and diabetes to depression and memory problems.
Senior author Danny Eckert puts it bluntly: ‘Irregular sleep is more than just feeling tired—it can be a health risk.’
Of course, the environment isn’t the only thing keeping us up at night. The study also points to family responsibilities, work commitments, socialising, bedtime procrastination (yes, that extra episode on Netflix counts!), and biological factors as key contributors to irregular sleep.
Let’s not forget the impact of the COVID-19 pandemic, which the researchers believe may have contributed to a gradual decrease in overall sleep duration, about 2.5 minutes less per night from 2020 to 2023.
So, what’s a sleep-deprived Australian to do? Here are a few tips to help you get the rest you need, no matter the season:
- Stick to a routine: Try to go to bed and wake up at the same time every day, even on weekends.
- Embrace the light: Get plenty of natural sunlight during the day, especially in winter, to help regulate your body clock.
- Keep it cool: Use summer fans, air conditioning, or light bedding to create a comfortable sleep environment.
- Wind down: Create a relaxing bedtime routine—think reading, gentle stretches, or a warm bath.
- Limit screens: Avoid screens for at least an hour before bed, as the blue light can affect melatonin levels.
- Listen to your body: If you’re feeling tired, don’t fight it—your body knows best.
Have you noticed your sleep changing with the seasons, or do you find yourself staying up later on weekends? Maybe you’ve got tips for getting a good night’s rest, no matter what the calendar says. Share your experiences and advice in the comments below.
Also read: Don’t ignore this sleep issue that triples your chance of dying early
