The sun set for the last time in Utqiagvik November 18th, 2022 and will not rise again for 67 days. During my 5 years teaching in the Arctic, I was lucky enough to experience 5 Polar Nights. Honestly, it was my favorite time of year. Please see my interview with Accuweather below to learn more about my experience.
The polar night is a phenomenon where the nighttime lasts for more than 24 hours that occurs in the northernmost and southernmost regions of Earth. This occurs only inside the polar circles.[1] The opposite phenomenon, the polar day, or midnight sun, occurs when the Sun remains above the horizon for more than 24 hours.
"Night" is understood as the center of the Sun being below a free horizon. Since the atmosphere refracts sunlight, the polar day is longer than the polar night, and the area that is affected by polar night is somewhat smaller than the area of midnight sun. The polar circle is located at a latitude between these two areas, at approximately 66.5°. While it is day in the Arctic Circle, it is night in the Antarctic Circle, and vice versa.
Any planet or moon with a sufficient axial tilt that rotates with respect to its star significantly more frequently than it orbits the star (no tidal locking between the two) will experience the same phenomenon (a nighttime lasting more than one rotation period).
The polar shortest day is not totally dark everywhere inside the polar circle, but only in places within about 5.5° of the poles, and only when the moon is well below the horizon. Regions located at the inner border of the polar circles experience polar twilight instead of polar night. In fact, polar regions typically get more twilight throughout the year than equatorial regions.
Photo of the last sunset before the beginning of Polar Night taken the in past 5 years. Print available at www.kirstenalburgstudio.com and purchases support little polar bear prints for children's hospitals.
For regions inside the polar circles, the maximum lengths of the time that the Sun is completely below the horizon varies from zero to a few days beyond the Arctic Circle and Antarctic Circle to 179 days at the Poles. However, not all this time is classified as polar night since sunlight may be visible because of refraction. The time when any part of the Sun is above the horizon at the poles is 186 days. The preceding numbers are average numbers: the ellipticity of Earth's orbit makes the South Pole receive a week more of Sun-below-horizon than the North Pole (see equinox).
Polar twilight occurs in areas that are located at the inner border of the polar circles, where the Sun will be on or below the horizon all day on the winter solstice. There is then no true daylight at the solar culmination, only civil twilight. This means that the Sun is below the horizon, but by less than 6°. During civil twilight, there may still be enough light for most normal outdoor activities because of light scattering by the upper atmosphere and refraction. Street lamps may remain on and a person looking at a window from within a brightly lit room may see their reflection even at noon, as the level of outdoor illuminance will be below that of many illuminated indoor spaces. It occurs at latitudes between 67°24’ and 72°34’ North or South, when the Sun does not rise, only civil twilight visible.
Polar Night photo from my gallery: www.kirstenalburgstudio.com
Sufferers of seasonal affective disorder tend to seek out therapy with artificial light, as the psychological benefits of daylight require relatively high levels of ambient light (up to 10,000 lux) which are not present in any stage of twilight; thus, the midday twilights experienced anywhere inside the polar circles are still "polar night" for this purpose.