Image: Esko Jämsä / AOP

The period of endless night known as polar night began in northernmost Finland in the town of Nuorgam on Friday. During this period, the sun will not rise above the horizon until January 17.

The period of semi-darkness will also begin in the country’s northernmost municipality Utsjoki on Saturday and will also end in mid-January.

From Utsjoki, polar night will progress further south to other areas inside the Arctic Circle.

The shadowy twilight period is caused by the earth’s tilt on its axis, which prevents sunlight from reaching some parts of the globe as it rotates.

Winter Solstice a promise of brighter days ahead

During the winter, the tilt means that no sunlight reaches the polar regions, even during the day. In the rest of the country, days will continue to shorten until December 21, the Winter Solstice. After that, days will gradually lengthen.

Although it may be hard to believe, places like Nuorgam in the far north and Hanko on the south coast enjoy the same amount of sunlight during the average year.

That’s because the nightless summer nights of the north, when the sun remains above the horizon, compensate for the seasons of extended darkness.

The reflective quality of snow will help northerners endure — and enjoy — the days when the sun remains below the horizon however. According to Yle meteorologist Toni Hellinen, Lapland currently has more snow cover than usual for this time of year.

In Kittilä, snow depth was recorded at 63 centimetres on Friday.