The answer to whether it is always day in Greenland is no, but the truth is complex. Greenland is a vast territory stretching across many latitudes, with a significant portion lying inside the Arctic Circle. This location makes its experience of daylight highly seasonal and location-dependent. Depending on the time of year, Greenland experiences two extreme light conditions: the continuous light of the Midnight Sun and the prolonged darkness of the Polar Night. These phenomena result from the physical mechanics of Earth’s orbit and tilt, creating a dramatic annual cycle that shapes life in the Arctic.
The Role of Earth’s Tilt and Latitude
The extreme variations in daylight are fundamentally caused by Earth’s astronomical orientation. Its rotational axis is tilted at approximately 23.5 degrees relative to its orbital plane around the sun. This axial tilt drives the seasons by determining which hemisphere receives more direct solar energy.
During the Northern Hemisphere’s summer, the tilt angles the North Pole toward the sun, causing rays to strike the Arctic at a steeper angle. In winter, the North Pole is angled away, leading to a lower sun angle and shorter days. This effect is pronounced beyond the Arctic Circle, located at approximately 66.5 degrees North latitude.
Locations north of this 66.5° N line are susceptible to periods where the sun either never fully sets or never fully rises for more than 24 consecutive hours. Since Greenland stretches from below the Arctic Circle well into the high Arctic, its settlements experience these light extremes based purely on their latitude; the farther north a town is located, the longer the annual period of continuous daylight or darkness will be.
Experiencing the Midnight Sun
The Midnight Sun is a summer phenomenon of perpetual daylight. This event occurs when the sun remains visible above the horizon for a full 24-hour rotation of the Earth. The duration of this continuous daylight is directly correlated with a location’s latitude within the Arctic Circle.
In southern towns like Nuuk (64° N), the sun still sets, but summer days are extremely long, lasting over 21 hours around the solstice. Even after sunset, the sky remains light with “white nights,” where the atmosphere scatters enough light to prevent true darkness. Nearly all of Greenland experiences very bright nights throughout the summer months.
The experience is more intense in high Arctic settlements. In Qaanaaq (77° N), the sun does not set for approximately three and a half months, lasting from mid-April until late August. This constant solar presence can affect the human body’s circadian rhythm, often making it difficult to maintain a normal sleep schedule. Many homes use specialized blackout curtains to help residents and visitors cope with the continuous daylight.
The Phenomenon of Polar Night
The counterpoint to the Midnight Sun is the Polar Night, which occurs in winter when the sun remains completely below the horizon for more than 24 hours. The length and intensity of the Polar Night depend entirely on latitude. Southern towns like Nuuk do not experience a true Polar Night, but instead have extremely short days, with daylight lasting only about four hours in December.
The full Polar Night is reserved for the northern regions. In Qaanaaq, the sun disappears below the horizon for nearly four months, from late October to mid-February. However, this period is often not one of absolute darkness, as the atmosphere refracts sunlight even when the sun is below the horizon.
For much of the Polar Night, a portion of the day is spent in varying degrees of twilight. Civil twilight occurs when the sun is less than six degrees below the horizon, providing enough ambient light for outdoor activities around midday. Only the most northern latitudes experience the deepest darkness, where the sky remains nearly black around the clock. This period of continuous darkness ends with the return of the sun, which is often celebrated by local communities.