Kun pimeys valtaa pohjoisen pallonpuoliskon

Polar night

What does polar night actually mean?

Polar night is a yearly time period during which the sun doesn’t rise above the horizon. The polar circle is a latitude that, in practice, matches with Earth’s axial tilt in respect of the Sun, and it marks the border for this phenomena. Due to this tilt, we have different seasons when different parts of Earth receive different amounts of the Sun’s energy during the year.

In the Northern Hemisphere, the winter solstice, or midwinter, takes place on December 21st or 22nd, and correspondingly in the Southern Hemisphere, on June 21st or 22nd, marking the halfway point of the polar night. The farther north you are, the longer the polar night. For example, in Sodankylä, Finland, the polar night lasts for 4 days, but in Utsjoki, Finland, for 52 days. This essentially means that in the municipality of Utsjoki, the sun cannot be seen for nearly two months! During this period, the sun cannot be used as a measure of time, and this high-latitude natural phenomenon is expressed by the upper dial of the Rohje watch. When traveling to the North Pole, you would experience the longest possible polar night, from the autumnal equinox in September until the vernal equinox in March – in other words, half a year.

The opposite of the polar night is polar day, also known as the midnight sun. During this time, the sun does not set at all. The sun can be seen going down towards the horizon and then rising back up again.