Seasonal Insomnia: Fact or Fiction?

Dr. Colleen Ehrnstrom, PHD
Oct 11, 20215 min read
Working at computer as the sun sets

Change is inevitable; sometimes change can be advantageous, sometimes inconvenient, but change will always be unavoidable. Similarly, for better or for worse, seasonal change can affect one's sleep.

Fortunately, the human body can adjust and adapt. Thus, although outside factors, such as the weather may influence sleep, the disruption is usually short-lived. In some instances, however, a more chronic insomnia may develop.

Read on to learn how this happens and what you can do about it.

What is Insomnia?

Insomnia is defined as any or all of the following;  trouble falling asleep, staying asleep, waking too early, or feeling tired during the day. Acute insomnia or short-term insomnia can last for a few days or a few weeks. It can often typically be connected to a number of external factors, such as the weather or upcoming deadlines, it is a completely normal response to change. Chronic insomnia is when you have trouble sleeping more nights than not for at least 3 days out of 7 for at least 3 months or longer. If left untreated, insomnia can adversely affect health.

How the Weather Affects Your Sleep

Bodies prefer to follow a predictable pattern of wake time and sleep time each day. These rhythms are largely regulated by our sleep drive and our circadian rhythm. Our sleep drive and circadian rhythm must line up with each other throughout the days and nights to support our body in falling asleep, staying asleep, and waking up. Our sleep drive is regulated by the quantity and quality of your sleep. Think of it like your hunger drive -- the more you eat, the fuller you get; likewise, the more you sleep, the more rest you get. Your circadian rhythm is your body’s internal clock that regulates many different bodily processes including your sleep and wake schedule.

Our circadian rhythm naturally runs a bit longer than 24 hours, and therefore relies on sunlight and temperature, to keep it in alignment with our days and nights.  Light exposure also influences the body’s production of the hormone melatonin. Melatonin serves as a time cue for sleep and helps you sleep. The body produces the hormone melatonin when sunlight levels drop.The body needs sunlight to make vitamin D, which regulates the production of the hormone serotonin. Lower serotonin levels lead to disruptions in sleep and are associated with greater daytime drowsiness and feelings of depression.

Research shows the ideal temperature for sleep is between 68-72 Fahrenheit. Indoor temperatures can fluctuate as the weather changes and this can create a less-than-ideal environment for sleep.

Finally, let’s not forget the challenges we all face in maintaining healthy lifestyle habits during the winter months. It is not always easy to go out for a run in freezing temperatures. Temptations such as sugar-filled holiday meals, late-night partying, and drinking can also impact our sleep.

This is why weather changes can have an impact on our sleep. When days become shorter, so does our exposure to natural sunlight, the strongest circadian rhythm adjustment tool. This change in light exposure not only impacts our circadian rhythm but also the timing of our melatonin production and our production of vitamin D. It also impacts our sleep environment and our ability to make healthy lifestyle choices that promote healthy sleep patterns.

Seasonal Insomnia – Myth?

While seasonal variations in sleep are common, whether they are directly responsible for chronic insomnia is debatable. For instance, a large-scale study on 43,045 participants in Norway found no evidence for seasonal insomnia. This is significant because Norway experiences major seasonal changes.

The 3P model is a widely accepted model that offers an explanation of what causes chronic insomnia. In this model, the onset of sleep difficulties is typically due to a precipitating factor (P #1) or a trigger, which could be a number of factors, and in this discussion, it's the seasonal changes in the weather. These changes interact with other factors that were already there, known as predisposing factors (P #2). Quite simply, what we have and what life gives us leads to the start of sleep problems. What differentiates insomnia that resolves versus insomnia that is chronic is how we learn to respond to our sleep challenges. Not being able to sleep often becomes stressful and becomes a source of anger and frustration. The more we try to sleep and become activated, the more difficult it becomes to sleep. This influences our thoughts and behaviors, often leading to attempts that are meant to “fix” the sleep problem but end up making it worse. These thoughts, feelings, and behavior become perpetuating factors (P #3) that maintain sleep disruption.

Like the name of the model, all three Ps (predisposing, precipitating, and perpetuating) factors create the insomnia spiral.  Seasonal changes impact our sleep, interact with other factors (such as pain or hormones), and lead to worrying about sleep and trying to manage our lack of sleep. This, in turn, increases physical activation, worry and stress, creating a vicious struggle with insomnia.

How To Sleep Better Regardless of The Weather

Evident from our discussion, seasonal change can certainly cause short-term sleep disturbances. However, when these seasonal changes lead to a more chronic insomnia pattern, this is a result of not just the seasonal changes, but what pre-existing challenges we had before the sleep problems and how we try to fix these sleep problems.   Fortunately, cognitive behavioral therapy for insomnia (CBT-I) is a proven method to treat behavioral insomnia. It focuses directly on the link between our thoughts, behaviors, and habits.

Sleep in any season is possible by addressing emotions and challenging our thoughts related to insomnia, and changing your habits with CBT-I.

Learn More

To get more information about seasonal sleep changes and use Dawn’s evidence-based CBT-I to treat your insomnia, contact us today!


Dr. Colleen Ehrnstrom, PHD

Dr. Colleen Ehrnstrom is a licensed clinical psychologist with a specialty practice in Acceptance and Commitment Therapy (ACT). Areas of expertise include insomnia and other sleep disorders, anxiety, and depression.

Dr Ehrnstrom is the co-author of the book End the Insomnia Struggle: A Step by Step Guide to Help you Get to Sleep and Stay Asleep which offers a comprehensive, personalized sleep program that integrates the physiology of sleep, cognitive behavioral therapy for insomnia (CBT-I) and acceptance and commitment therapy (ACT).

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