Midnight sun facts for kids
The Midnight Sun, also known as polar day, is an amazing natural event. It happens during the summer months in places far north of the Arctic Circle or far south of the Antarctic Circle. During this time, the Sun stays visible in the sky even at local midnight!
This special sight occurs in areas roughly between 65°44' and 90° north or south. It doesn't stop exactly at the Arctic or Antarctic Circles. This is because light bends as it passes through Earth's air, a process called refraction.
The opposite of the Midnight Sun is called polar night. This happens in winter when the Sun stays below the horizon all day long.
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What is the Midnight Sun?
The Midnight Sun is when the Sun never fully sets below the horizon for more than 24 hours. Imagine playing outside late at night, but it's still bright like daytime! This happens because of how Earth tilts as it travels around the Sun.
Where Can You See the Midnight Sun?
Since there are no permanent towns or cities south of the Antarctic Circle (only research stations), most people who experience the Midnight Sun live in places crossed by the Arctic Circle.
Cities and Countries with Endless Days
Many countries and regions get to see the Midnight Sun. For example, Big Diomede Island in Russia sees the Sun all day from June 18 to 24.
Murmansk, Russia, is the largest city north of the Arctic Circle. About 270,000 people live there. They enjoy the Midnight Sun from May 22 to July 22, which is 62 days!
A big part of Finland is north of the Arctic Circle. In the very northernmost part of Finland, the Sun doesn't set for 72 days during summer.
In Svalbard, Norway, which is Europe's northernmost inhabited area, the Sun stays up from around April 19 to August 23. On mainland Norway, cities like Tromsø also see the Midnight Sun from late May to mid-July. Many visitors come to these places to enjoy outdoor activities under the never-setting Sun.
The most extreme places are the poles themselves. At the North Pole, the Sun is visible for about six months, from around March 18 to September 24. The South Pole in Antarctica also has six months of daylight, from about September 20 to March 23.
Seeing the Sun Beyond the Circles
Because of how light bends in our atmosphere (this is called atmospheric refraction), and because the Sun looks like a big circle, not just a tiny dot, you can sometimes see the Midnight Sun even a little bit outside the polar circles. This usually doesn't go beyond one degree of latitude.
For example, most of Iceland is just south of the Arctic Circle, but it's still famous for its Midnight Sun. This is why the poles also have slightly more than six months of sunlight. Even the northern parts of the United Kingdom experience a bright twilight in the northern sky around the summer solstice.
In places very close to the poles, like Alert, Nunavut in Canada, it never gets completely dark at night, but the Sun also doesn't fully rise during certain times. This creates a mix of Midnight Sun and polar night effects.
Why Does the Midnight Sun Happen?
The Earth doesn't spin perfectly straight up and down. It has a tilt, like a leaning top. This tilt is about 23.5 degrees. Because of this tilt, as Earth orbits the Sun, one of its poles (either the North or South Pole) leans towards the Sun during its summer.
When a pole leans towards the Sun, that part of the Earth gets continuous sunlight. The Sun appears to move in circles around the sky without setting. At the poles themselves, the Sun rises and sets only once a year, around the equinoxes. For six months, it stays above the horizon, slowly spiraling higher until the summer solstice, then sinking lower until it sets after the autumnal equinox.
When the Sun Stays Low: White Nights
In some places, the Sun doesn't set, but it also doesn't get very high in the sky. This creates a long, bright twilight that lasts all night. These are called "White Nights." During White Nights, it's bright enough to do daytime activities, like reading, without needing artificial lights.
This happens in areas between about 60°34’ latitude and the polar circles. It occurs during both the Northern Hemisphere summer and Southern Hemisphere summer.
White Nights are a famous symbol of Saint Petersburg, Russia. They happen there from about June 11 to July 1. The last 10 days of June are celebrated with a special White Nights Festival of cultural events. Fairbanks, Alaska, also celebrates this phenomenon. They have an annual Midnight Sun Game baseball competition played around midnight on June 21.
The northernmost tip of Antarctica also experiences White Nights around the Southern Hemisphere summer.
How Long Does the Midnight Sun Last?
The closer you get to either the North or South Pole, the more days you will experience the Midnight Sun each year. While it's generally defined by the polar circles, you can sometimes see the Midnight Sun up to 90 kilometers (about 56 miles) outside these circles. The exact timing can change slightly each year.
At the Arctic Circle, you can see some part of the Midnight Sun from about June 12 until July 1. As you travel further north, this period gets longer. For example, at Cape Nordkinn, Norway, the northernmost point of mainland Europe, the Midnight Sun lasts from about May 14 to July 29. On the Svalbard islands, even further north, it lasts from April 20 to August 22.
Longest Days at the Poles
The periods of continuous daylight and darkness are not exactly equal at the poles. This is because Earth's orbit around the Sun isn't a perfect circle. Earth is closest to the Sun (at perihelion) in early January and farthest away (at aphelion) in early July.
Because of this, the polar day is longer than the polar night in the Northern Hemisphere. For instance, in Utqiagvik, Alaska, the polar day lasts 84 days, while the polar night is only 68 days. In the Southern Hemisphere, it's the opposite: the polar night is longer than the polar day.
At the North Pole itself, the polar day lasts for 186 days, and the polar night is 179 days. At the South Pole, the polar day is 179 days, and the polar night is 186 days.
If you are high up, like on a mountain, you might see the Midnight Sun for even longer. This is because your view of the horizon is lower.
Clocks and the Midnight Sun
The term "Midnight Sun" usually means 24 hours of sunlight in the polar regions. However, sometimes the time you see the Sun at midnight can be affected by things like time zones and if a place uses daylight saving time.
For example, in Fairbanks, Alaska, which is just south of the Arctic Circle, the Sun might set at 12:47 a.m. during the summer solstice. This isn't because of the true Midnight Sun phenomenon, but because Fairbanks' local clock time is set ahead of its actual solar time.
So, while the Sun is always visible at true solar midnight in the polar regions during summer, what your clock says "midnight" is can be a bit different!
See also
In Spanish: Sol de medianoche para niños
