Do we really need more sleep in winter? Science says yes

The alarm goes off in the dark, the evening arrives by mid-afternoon, and by 9 pm the sofa looks like the best place on earth. Winter fatigue tends to feel like a personal failing, a lapse in discipline you should have fixed by now. New research suggests it may be a seasonal pattern worth respecting.

Meet the Berlin sleep study

Researchers at St Hedwig Hospital in Berlin, led by Dr Dieter Kunz, analysed overnight sleep studies from 188 adults across the year. In winter, participants spent about 30 minutes longer in REM sleep (rapid eye movement sleep) than in spring.

Total sleep time appeared to be up to an hour longer in winter too, although that difference wasn't considered statistically significant. Deep sleep stayed fairly stable from winter to summer but was shorter in autumn, and REM sleep latency, the time it takes to reach the first REM stage, was shorter in autumn than in spring.

Read the findings with some caution

The participants were patients at a sleep clinic, many with insomnia, depression or sleep-related breathing disorders. That's a limit worth taking seriously. Dr Kunz has said the work needs to be replicated in a larger, healthy population before anyone draws firm conclusions.

Still, the pattern fits an idea researchers call human seasonality. Sleep architecture, meaning the way your sleep cycle moves through its stages overnight, may shift with the seasons. In this study, the composition of sleep changed more clearly than the total hours.

Understand how winter light shapes your body clock

Your circadian rhythm is the internal clock that guides your sleep-wake cycle, and light is one of its strongest cues. During the darker and colder months, daylight hours shrink, and many of us get far less natural light exposure than in summer, while artificial light fills the gap indoors.

Research suggests our natural sleep patterns may still follow the seasons, even in an urban environment. That could help explain why so many people feel sleepier in winter and find it harder to get out of bed. Colder temperatures and changing light can both play a part in how rested you feel.

Recognise seasonal affective disorder

Feeling slower in December is common. Seasonal affective disorder is different. The NI Direct guidance describes it as a type of depression that comes and goes in a seasonal pattern, with symptoms that can include low mood, sleeping longer than normal and finding it hard to get up in the morning.

If you think you might have it and you're struggling to cope, consider seeing your GP. The same goes for ongoing sleep difficulties or suspected sleep disorders, which deserve proper attention at any time of year.

Adjust your habits to match the season

Dr Kunz suggests going to bed earlier in winter may help match our seasonal sleep needs. If you want to sleep earlier, shift your bedtime by 10 to 15 minutes every few days instead of making one big jump, so your body has time to follow. Small tweaks are easier to keep up than big overhauls, so pick one change and start there.

Morning sunlight is the next lever. Open the curtains as soon as you wake, and if you can, get outside before midday, since NI Direct advises as much natural sunlight as possible alongside regular exercise, particularly outdoors in daylight.

Regular exercise helps too, ideally outdoors so you pick up daylight at the same time. A brisk lunchtime walk counts. It may give your body clock a clearer daytime signal, making it easier to feel sleepy at the right hour as evening arrives.

Keep expectations realistic as well. An extra half hour in bed may suit you better than a full hour, and needs vary from person to person. Notice how you feel over a couple of weeks, then adjust from there.

Protect your evenings and mornings

In the evening, dim the lights and put screens away to keep disrupted sleep at bay. If streetlights or an early glow through the curtains find their way in, a sleep mask is a simple way to keep light out of your eyes.

Keep your waking time steady too, even at weekends, because a consistent rhythm makes both bedtime and the alarm clock easier to live with.

If you wake up still tired, try adding extra rest instead of fighting it. An earlier night or a slower morning is a reasonable response to shorter days, and a healthy sleep routine can flex a little as the seasons change.

Give yourself permission to rest

Wanting more sleep in the winter months is common, and the science so far suggests a biological need behind it. So go easy on yourself. Build in earlier evenings, catch the morning light, and treat the extra rest as part of looking after your well-being until the daylight returns. Once the days start to lengthen again, your sleep habits can ease back into their usual rhythm.