Does Our Sleep Needs Change Seasonally?

Hate waking up when it’s dark out? Find out how winter really affects your sleep habits.

With the holidays over and everyone back to school and at work, it is easy to feel more bummed out. The days are getting longer each day but we are still waking up and coming home in the dark, and maybe some of us are really starting to feel the effects of winter.

nightdrivingIf you feel sleepier in the winter and more bright-eyed in the summer, you’re not alone. Your circadian rhythm, which regulates your body clock, is maintained by exposure to light. And in the winter, especially in northern latitudes where the daylight hours are especially short, light can be scarce. While seven to nine hours of sleep is still a healthy benchmark year-round, you may find that you need an hour or two more than you did in the sunny days of summer to feel bright-eyed.

Of course, in modern times, with no shortage of electricity to light the post-sunset (and pre-dawn) hours, we are less limited by the sun than our ancestors might have been. In fact, some scholars believe that before the 19th century, it was common for people to spread a typical eight-hour night of sleep spread out over about 12 hours of darkness, especially during the long nights of winter. They would sleep for about four hours, wake up to pray, meditate, talk, or write by candlelight, and then go back to sleep again until daylight.

These days, it’s easy to flick on a light when the alarm goes off at 6:00am, even if it’s still pitch dark outside in January. But as many as 90 percent of guy sleeping people’s moods and energy levels are affected by changes in the seasons. For about four to six percent of individuals, that can escalate to seasonal affective disorder (SAD), a form of clinical depression that fluctuates based on the time of year. Meanwhile, as many as 20 percent experience a more mild form of winter blues. And with both of these diagnoses can come symptoms that affect your sleep, including loss of energy and needing 1.75 to 2.5 extra hours of sleep each night (for SAD and the winter blues respectively).

Sleeping too much can be unhealthy, regardless of the season, so if you’re already getting seven to nine hours of zzz’s per night and you’re still not feeling rested, talk to your doctor about getting tested for a sleep disorder. If it’s winter—and lack of light that has you down—simple lifestyle tweaks like getting regular exercise (ideally in sunlight) or using an artificial light box may help to get your body clock back on track.


This blog does not provide medical advice. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on If you think you may have a medical emergency, immediately call your doctor or dial 911.

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