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Nov 13, 2026

Kaamos and sleep: how the polar night affects rest in Lapland

Every winter guests ask us the same thing over breakfast: why am I so sleepy here? Kaamos, the Finnish word for the dark season of the polar night, is part of the answer. When daylight becomes short and dim, the body’s internal clock loses its strongest signal, and many people sleep longer without feeling better for it.

We live with kaamos every year in Rovaniemi. In this post we explain what Finnish health researchers say about kaamos and sleep, using the Finnish sources listed at the end, and how we build our own dark-season evenings around light, routine and a warm sauna.

In short: according to the Finnish medical library Terveyskirjasto, typical kaamos symptoms include long but unrefreshing sleep, evening cravings for sweet food and tiredness. They usually start in October, peak from November to January and ease by late February. Finnish experts recommend daylight outdoors, especially in the morning, regular exercise, regular meal times and, when symptoms are strong, bright light therapy. If your low mood or sleepiness is severe or lasts, talk to a doctor.

At a glance

• From: 159 €
• Experience type: Sauna
• Duration: 1 hour 30 minutes
• Included: Bathrobes & Slippers; Towels; Seat covers; Soft drinks & water; Small lounge area; Private Sauna use; Private Jacuzzi use

What kaamos is

Kaamos is the polar night: the time of year when the sun stays below the horizon. As thisisFINLAND explains, it only occurs above the Arctic Circle. It lasts almost two months in Utsjoki on Finland’s northern border and only a few days in Sodankylä, further south near the Arctic Circle. In Rovaniemi, which sits on the Arctic Circle, the darkest weeks come around the winter solstice in late December.

Kaamos is rarely pitch black. Because the sun is not far below the horizon, some sunlight still reaches the upper atmosphere, which gives the typical blue twilight of northern Finland. Moonlight reflects off the snow, and on clear nights the northern lights may appear. We have written more about this in our posts on the polar night in Rovaniemi and December daylight in Rovaniemi.

Why darkness changes the way we sleep

Our sleep and waking follow an internal daily rhythm, and light, above all morning light, is what keeps that rhythm on time. That is why the Finnish self-care advice for the dark season starts with getting outdoor light, especially in the morning.

Timo Partonen, a psychiatrist and research professor at the Finnish Institute for Health and Welfare (THL), describes the typical kaamos pattern in the Terveyskirjasto health library:

• sleep becomes longer, but does not feel refreshing
• cravings for sweet and starchy food, especially in the evening
• weight often increases
• tiredness, lower mood and less interest in doing things

The same article says the symptoms usually appear in October, are strongest from November to January and ease by late February.

How common kaamos symptoms are in Finland

Most people who feel sleepy in winter do not have an illness. According to Terveyskirjasto, 1–2% of people in Finland have seasonal depression (kaamosmasennus), while a further 20–30% have milder kaamos symptoms without a diagnosis.

A study from the University of Eastern Finland and THL looked at 636,543 sick leaves for mental-health reasons over 12 years. Sick leaves for depression, anxiety and sleep disorders rose clearly in October and November, and in late autumn they were almost twice as high as in summer. The researchers also note that winter depression often brings excess sleepiness, and that its symptoms can often be eased with bright light therapy.

How locals cope, according to Finnish health experts

The self-care advice in Terveyskirjasto is practical and not very glamorous, which is exactly why it works as a winter routine:

• Get outdoor light, especially in the morning. Even a grey winter day outdoors is brighter than most rooms.
• Move regularly. The article suggests aerobic exercise for 45–60 minutes, two or three times a week.
• Eat at regular times. Regular meals help keep the daily rhythm steady.
• Keep in touch with people. Staying social is part of the advice too.

A THL study following people from Tampere from age 16 to 52 found that people with a strong evening rhythm had more insufficient sleep and more depressive symptoms, and that a modest shift towards a morning rhythm was linked to fewer psychological symptoms. In everyday terms: a steady rhythm matters.

Bright light therapy, the Finnish way

Many Finnish homes and offices have a bright light lamp for the dark months. According to Terveyskirjasto, light therapy uses 2,500–10,000 lux, usually for about 30 minutes at first, and works best in the morning, ideally soon after waking, at least five days a week. The HUS Helsinki University Hospital service Mielenterveystalo says that at 2,500 lux sessions typically last one to two hours, that 5,000–10,000 lux allows shorter sessions, and that symptoms often improve considerably within one to two weeks.

Both sources mention possible side effects such as headache or eye irritation, so this is something to discuss with a health professional rather than improvise. For persistent low mood, please see a doctor.

If you are only visiting for a few days

A short winter trip is not the same as living through months of kaamos, but the same basic ideas apply to feeling well on holiday. Spend the brightest hours around midday outdoors, keep your meals and bedtime roughly regular even when an evening tour runs late, and do not worry if you sleep a little more than at home.

Our own programme follows the light: daytime activities make the most of the few bright hours, and evenings are for the northern lights, the sauna and rest.

How this shows up on our tours

In our family, the dark-season evening often ends in the sauna. At Aurora Hill Resort, about 10 km from the city centre, we run the Private Traditional Finnish Sauna & Jacuzzi use at Aurora Hill Resort: 1 hour 30 minutes, from 159 €. It follows the old way of bathing: there is no shower, and water is heated in a tank on the stove and mixed with cold water, so you wash by pouring it over yourself with a ladle. You have a private jacuzzi too, and can move between the sauna, the jacuzzi and the snow.

Bathrobes and slippers, towels, seat covers, soft drinks and water, a small lounge area, and private use of the sauna and jacuzzi are included. Guests staying at Aurora Hill also get free access to the Northern Lights Alert App, with three sensitivity levels, so you do not have to stay awake watching the sky: the app can wake you if the lights appear over the resort.

Prefer a wood-heated sauna with a cold plunge? Our Private Wooden Heated Sauna and Ice Swimming lasts 4 hours, from 398 €, with an ice hole, winter clothing, snacks and pick-up included. More about our saunas: StayLapland sauna experiences.

Frequently asked questions

What does kaamos mean?

Kaamos is the Finnish word for the polar night, the dark season when the sun stays below the horizon above the Arctic Circle.

Why do I feel so sleepy in Lapland in winter?

Short, dim days weaken the light signal that keeps the body’s daily rhythm on time. Finnish sources describe longer but less refreshing sleep as a typical kaamos symptom.

How many Finns get kaamos symptoms?

According to Terveyskirjasto, 1–2% of people in Finland have seasonal depression and a further 20–30% have milder kaamos symptoms.

What do Finns do to cope with kaamos?

Finnish health advice recommends outdoor light, especially in the morning, regular exercise, regular meal times, keeping in touch with people and, when needed, bright light therapy discussed with a health professional.

What is included in the private sauna at Aurora Hill Resort?

Bathrobes and slippers, towels, seat covers, soft drinks and water, a small lounge area, and private use of the sauna and jacuzzi. The session lasts 1 hour 30 minutes, from 159 €.

Is it completely dark during kaamos?

Rarely. Some sunlight still reaches the upper atmosphere, which gives the blue twilight of the polar night, and snow reflects moonlight.

Ready to book?

You may also like

• Private Wooden Heated Sauna and Ice Swimming — from 398 €, 4 hours
• Traditional Finnish Sauna Experience — from 149 €, 4 hours

Sources

• Terveyskirjasto (Duodecim): Kaamosmasennus, Timo Partonen
• Mielenterveystalo.fi (HUS): Kirkasvalohoito kaamosmasennukseen
• University of Eastern Finland: Connection between light levels and mental health
• THL: Vuorokausirytmin pysyvyydellä on merkitystä mielenterveydelle keski-iässä
• thisisFINLAND: When the sun doesn’t rise in northern Finland