Even when we’re exposed to artificial light, new research shows humans experience seasonal sleep to beat winter fatigue.
As the temperature drops and the days grow shorter, bed becomes all that more appealing. Hitting the snooze button for an extra 10 minutes in the morning and battling afternoon slumps during the darker afternoons are familiar for a lot of us.
With over 1/3 of adults reporting they feel more tired in winter months, is there a scientific reason behind our winter fatigue? Recent studies have found that seasonal changes may impact our biological need for more rest.
Do we need more sleep in winter?
In short, yes. Your circadian rhythm (eg sleep-wake cycle) is your internal body clock that is influenced by light and dark. So as the hours of sunlight adjust, so does our sleep pattern. Studies have shown that the length of sleep and quality of sleep fluctuates with the seasons: we get the most amount of sleep in winter months, and our least amount of sleep in summer months.
New research in a 2023 study, found that people naturally get up to 1 hour more sleep, and approximately 30 minutes more REM (rapid eye movement) sleep in winter months. This need for extra sleep even occurs in people who live in urban environments, when artificial light can override natural sleep cycles - suggesting the impact would be even more profound if we still slept under the stars.
We need 30 minutes more REM sleep during winter, which is the most active stage of sleep that plays a role in memory consolidation, emotional processing and dreaming.
Why do we need more sleep in winter?
There’s a few reasons why we can feel more tired in winter and crave those extra minutes (or hours) of rest.
Less light exposure
Our internal body clock (circadian rhythm) is regulated by daylight hours. So when there is less sunlight in winter months, it can shift our natural sleep patterns. Morning sunlight triggers our bodies to wake up, so darker mornings delays the signal for our brains to wake up. When the sun sets, the body generates melatonin, the hormone that makes us sleepy. So darker evenings can make us feel ready for bed earlier than in summer months.
Colder temperatures
Being cold doesn’t directly cause us to feel tired (in fact it can make us feel more awake, in the case of cold water therapy). But when it’s cold outside, we tend to whack the central heating on which can make us feel more lethargic. Our bodies can also respond to colder temperatures by conserving energy and working hard to keep warm, which can manifest as a desire for more sleep.
Impact of Daylight Saving Time
The shift in time during autumn can throw off our internal clocks. When the clocks "fall back" in autumn, it can temporarily disrupt our sleep pattern, making it harder to wake up in the morning and easier to feel sleepy earlier in the evening. However, this change in time can help us regulate our longer term sleep habits by adjusting our wake up times to when there is more light.
5 tips to sleep better in winter
Whilst it’s normal to sleep a little more in winter, it’s important not to oversleep. Try not to exceed 9-10 hours a night if you can. Here are some expert tips for getting good sleep in winter and maintaining a good sleep hygiene.
1. Avoid hitting the snooze button
It might be tempting to hit snooze on those dark, chilly mornings, but hitting snooze can disrupt your sleep cycle and leave you feeling groggier. This is because when you drift back into sleep, you start a new cycle which is interrupted again and again. Instead, try to get up with your first alarm. This helps maintain a consistent wake-up time, which is essential for regulating your internal clock.
2. Go to bed earlier, but keep regular sleep schedule
As we tend to have work commitments in the morning which guide our wake up time, it’s easier to get the extra rest you need by going to bed earlier. However, the key is consistency. Try to go to sleep and wake up at the same time every day, even on weekends.
3. Continue walking and exercising, whatever the weather
Staying active is vital, especially in winter. In fact, being out in bad weather is good for you. Regular exercise, like walking, can help regulate your sleep patterns. Plus, immersing yourself in nature can help boost your mood, especially if you suffer with Seasonal Affective Disorder (SAD).
4. Try light therapy lamps
Light therapy lamps, such as Lumie lamps, can be a great tool to combat the limited daylight hours. These lamps mimic natural light and can be particularly beneficial in the morning, helping to kickstart your day and regulate your circadian rhythm. You can also pop them on if you need a little boost to your mood!
5. Expose yourself to natural light during the day
Make the most of the daylight hours by exposing yourself to natural light - first thing in the morning if you can! Whether it’s a short walk during your lunch break or opening blinds and curtains at home, natural light exposure is crucial for maintaining your circadian rhythm and boosting your mood during the shorter days.
So try not to feel guilty or lazy if you’re getting more rest during winter months - it’s normal for us to feel like this. In fact, it’s even likely that this need is linked to our evolutionary past. As Neil Stanley, a sleep expert at Sleep Station, told the BBC: "We have evolved to dark-light cycles, so when we wake up on a winter's morning and it's dark, our brain is going 'I can't do anything…there's no point leaping out of bed'.”
