The Science Behind Endless Daylight
The phenomenon of the sun remaining visible for 24 hours a day in certain parts of the world stems from Earth’s axial tilt. Our planet spins on an imaginary axis tilted approximately 23.5 degrees relative to its orbital plane around the sun. This tilt causes one of the poles to be continuously angled towards the sun during its summer months. As Earth rotates, the area around that pole remains exposed to direct sunlight, resulting in perpetual daylight.
The Arctic and Antarctic Circles mark the approximate boundaries where this phenomenon occurs. These imaginary lines are located at about 66.5 degrees north and south latitude, respectively. Any location situated north of the Arctic Circle or south of the Antarctic Circle experiences at least one day of 24-hour sunlight each year.
Regions of Constant Sunlight
In the Northern Hemisphere, many places within the polar regions, such as Norway, Sweden, Finland, and parts of Russia, experience periods of “midnight sun” during the summer months. For instance, in Norway, areas like North Cape and the Svalbard archipelago experience continuous daylight from late April to late August.
Vast regions of North America within the Arctic Circle also experience this phenomenon. Alaska in the United States and large portions of Canada’s northern territories (Yukon, Nunavut, Northwest Territories) have extended periods of 24-hour daylight, typically between May and July. Greenland and Iceland, situated near or partially within the Arctic Circle, also experience prolonged daylight.
The Southern Hemisphere also experiences continuous daylight. The entire continent of Antarctica, for example, has constant sunlight during its summer, which spans from October to March.
Life Under the Midnight Sun
Living in or visiting regions with constant daylight introduces unique adjustments for both humans and wildlife. Human sleep patterns can be disrupted because the absence of darkness interferes with the body’s natural production of melatonin, a hormone that regulates sleep. Many residents use blackout curtains to create artificial night environments for better rest.
Daily routines in these areas often extend into normal nighttime hours, with people engaging in outdoor activities at all hours. Tourism flourishes during these periods, as visitors come to experience the novelty of perpetual daylight and participate in activities like late-night hiking or golfing. Wildlife, such as birds and caribou, also adapt their cycles, remaining active for longer periods due to the continuous light.