5 Ways Winter Affects Your Sleep, According to Experts
Winter affects sleep by messing with your mood, drying out the air, and much more.

Each season affects your body differently. And winter in particular can send your REM cycle spiraling. During the colder months, your body goes through various changes in order to keep warm as the temperatures drop. But what does this mean for your sleep exactly? Well, there are both positive and negative ways in which winter affects your sleep. Keep reading to learn how exactly the season affects your snoozing time—and what you can do to make sure you catch those Z's!
Your sleep-wake cycle changes.
In the winter, we all know there's a lack of sunlight. As early as November, it's pitch black outside well before dinnertime! Unfortunately, that lack of sunlight means more melatonin, the so-called "sleep hormone" responsible for the regulation of your sleep-wake cycle.
"Light directly impacts the pituitary, which secretes melatonin," Brad Lichtenstein, ND, chair of the homeopathy department at Bastyr University's School of Naturopathic Medicine, told AccuWeather. And the less sunlight your body absorbs, the more melatonin it produces, which can make you feel sluggish and fatigued.
The good news? There are things you can do to counteract the effects of this lack of light. "Keep the lights on in the house, make it as bright as possible, and avoid napping in the evening to help get better quality sleep at night," suggests Shelby Harris, PsyD, CBSM, a licensed psychologist, board-certified behavioral sleep medicine expert, and author of The Women's Guide to Overcoming Insomnia.
Mood changes make you want to sleep more.
Not only does your body produce more melatonin in the winter, but as the National Sleep Foundation explains, mood changes during the coldest season of the year also cause the average person to want to sleep more.
"As many as 90 percent of people's moods and energy levels are affected by changes in the seasons," the organization notes. In severe cases, people experience seasonal affective disorder (SAD) or winter blues, both of which "can come [with] symptoms that affect your sleep, including loss of energy and needing 1.75 to 2.5 extra hours of sleep each night," the foundation notes.
But your stress hormone levels decrease.
Though you might think that summer would be the season associated with lower stress levels, science says otherwise. When a Polish research team analyzed the seasonal cortisol levels of female subjects in 2018, they found that the women had higher levels of the stress hormone during the summer.
Since cortisol interferes with the sleep cycle and can even cause insomnia, these findings indirectly showed that winter positively impacts sleep, too.
Dry air makes sleeping more difficult.
In the winter, the air becomes almost entirely devoid of moisture. This lack of humidity, as the National Sleep Foundation explains, "can irritate your throat and trigger fits of coughing or even gagging, which in turn makes sleeping difficult."
If you're already under the weather, sleeping in this dry environment can also exacerbate your condition, making it hard to fall (and stay) asleep. During the winter, try using a humidifier at night to avoid these sleep-disrupting seasonal effects.
And sleeping with the window open can disrupt your Z's.
Sometimes in the winter, sleeping with a cool breeze blowing into your bedroom is a nice way to counterbalance the blasting heat. Though this might help you cool down enough to fall asleep, it isn't great as far as staying asleep is concerned. One 2017 study published in the journal Energy and Buildings found that when subjects had an intense stream of cold air blowing directly on them, they moved more in their sleep, had higher heart rates, and woke up more throughout the night.
What's more, sleeping with the window open can make the temperature in your bedroom less than ideal for sleeping. "The ideal sleep temperature is in the mid- to upper 60s," explains Harris. "If you're somewhat cold, sleep with socks on, but don't keep yourself too warm as that can make it harder to fall asleep and stay asleep. Same goes for being too cold."