The sun does not set at the North Pole for nearly six months each year. Located at 90 degrees North latitude, the exact geographic North Pole experiences the most extreme light cycle on Earth, which is dictated by the planet’s orientation in space. This unique annual pattern means the sun remains continuously visible above the horizon for half the year, followed by a corresponding period when it remains below the horizon.
Earth’s Axial Tilt and the Arctic
The root cause of the North Pole’s unusual day-night cycle is the Earth’s axial tilt, which is approximately 23.5 degrees relative to the plane of its orbit around the sun. This tilt means that as the Earth revolves, the North Pole is angled directly toward the sun for one half of the year and angled away for the other half. The tilt remains fixed in space, constantly pointing toward the star Polaris.
The geographical boundary for this phenomenon is the Arctic Circle, an imaginary line situated at about 66.5 degrees North latitude. This circle defines the southernmost limit where the sun can remain visible for a full 24 hours at least once a year. The North Pole is far north of this circle, experiencing the most exaggerated version of the polar light cycle.
The Period of Perpetual Daylight
The period when the sun does not set at the North Pole is known as the polar day or the “Midnight Sun.” This half-year of continuous daylight begins around the time of the Vernal Equinox in late March, when the sun first appears to rise above the horizon. The North Pole is continuously bathed in sunlight from this moment as the Earth’s northern axis is tilted toward the sun.
The sun does not appear to rise and set daily during this time; instead, it slowly spirals upward in the sky until it reaches its highest point around the Summer Solstice in late June. It then begins a gradual, six-month descent, circling the horizon a full 360 degrees every 24 hours without ever dipping below it. This visual experience is striking, as the sun remains low in the sky, casting long, dramatic shadows.
At the exact North Pole, the sun remains above the horizon for approximately 186 days, from late March until late September. Locations within the Arctic Circle experience a shorter period of the Midnight Sun, with the duration increasing steadily closer to the pole. The phenomenon ends around the Autumnal Equinox, when the sun finally sinks below the horizon, initiating the next phase of the annual cycle.
The Long Stretch of Darkness
The inverse phenomenon to the Midnight Sun is the polar night, which begins when the sun sets around the Autumnal Equinox in late September. This period lasts until the sun reappears near the Vernal Equinox in late March, meaning the sun remains below the horizon for nearly six months. However, the entire six-month stretch is not one of absolute darkness.
The atmosphere refracts sunlight, which means that even when the sun is below the horizon, its light can scatter and illuminate the sky, creating periods of twilight. The darkest time is defined as true night, which occurs only when the sun is more than 18 degrees below the horizon. At the North Pole, this true, astronomical darkness lasts for only about 11 weeks, centered around the Winter Solstice in late December.
Before and after this deepest dark, the North Pole experiences lengthy periods of twilight. Civil twilight, the brightest phase where normal outdoor activities are possible, occurs when the sun is less than six degrees below the horizon and can last for weeks as the sun slowly sinks. This is followed by nautical twilight (sun 6–12 degrees below) and then astronomical twilight (sun 12–18 degrees below), which still provides a faint glow on the southern horizon, preventing the sky from becoming completely star-filled during the entire six-month span.