Midnight Sun: Why the Sun Stays Up All Night Near the Pole

In the far north in June, the Sun can stay above the horizon through the whole night. Around midnight it sinks toward the north, skims low, and then climbs again without setting. People call this the midnight Sun. It is not a trick of the clock or the weather. It follows from the tilt of Earth's axis.

This guide explains where the midnight Sun happens, why its edge sits near 66.5 degrees north, and how long it lasts in different places. It ends with a task in the Orbit Dial: finding the Arctic Circle, the lowest latitude where the Sun stays up all day on the June solstice.

What the midnight Sun is

NOAA describes the extreme case at the North Pole. In summer the Sun is always above the horizon there, circling the pole once every day. The same page uses the name Midnight Sun. Farther south the effect is shorter but real. NASA notes that in the northern parts of Alaska the Sun does not set for days or weeks on end at this time of year. It adds that Alaska is the only U.S. state that lies partly within the Arctic Circle.

NASA describes the Arctic Circle as the edge of the region where you can get 24 hours of sunlight or 24 hours of darkness. The National Snow and Ice Data Center puts it in one line: along the circle, the Sun does not set on the day of the summer solstice and does not rise on the day of the winter solstice.

Why the circle sits near 66.5° N

NASA gives Earth's axial tilt as 23.4 degrees. On the June solstice, the Sun's center is 23.4 degrees north of the plane of the equator. The Naval Observatory's data service lists the Sun's declination on June 21, 2026 as about 23.44 degrees. Declination is the angle between the Sun's center and the plane of the equator.

Here is the picture. Stand at the North Pole on that date and the Sun circles the sky about 23.4 degrees above the horizon. Walk south and each degree of latitude lowers the circling Sun by one degree. After 23.4 degrees of walking, the Sun's lowest point, at midnight, just touches the horizon. That spot is 90 minus 23.4, or about 66.6 degrees north.

The Naval Observatory's computed heights of the Sun at local midnight on June 21, 2026 follow that rule. The Sun gets one degree higher for every degree of latitude you add.

Sources round the circle's latitude in different ways. The National Snow and Ice Data Center says about 66°33′ N. NOAA's Arctic FAQ gives 66°34′ N in one answer and 66°32′ N in another, and says the exact position varies slightly over time. The National Weather Service uses 66.5°. These are one line with different roundings.

NASA Goddard's navigation lesson shows the winter mirror of the same rule. The noon Sun's height on the December solstice is (90 − 23.5) minus the latitude, and when that comes out negative the Sun never rises that day.

How long the light lasts

The circle itself gets more than one day of midnight Sun. The National Weather Service says the Sun never sets at 66.5° N from early June to early July. The reason is that the Sun is not a point. The Naval Observatory counts a day as daylight if any part of the Sun is above the horizon, and it allows for the bending of light by air. At 66.5° N the Sun's center sits just below the horizon at midnight, yet the table counts the day as lit.

Here are the stretches of 24-hour daylight in the Naval Observatory's 2026 tables.

The first three rows come from the Naval Observatory's daylight tables. The pole row comes from the National Weather Service. The National Weather Service describes Barrow, Alaska, which it places slightly north of 71° N, as having total light from mid-May to early August. That matches the 71.3° N row. The Naval Observatory warns that at high latitudes the result can depend on longitude and time zone, and that unusual bending of light can shift sunrise and sunset by a lot.

The dark mirror

The same geometry gives polar night in winter. The National Weather Service says Barrow has about two months of total darkness, with no sunrise for about a month on each side of the December solstice. At the North Pole, NOAA says there is no sunlight or even twilight from early October to early March.

Common mistakes

• Picturing a high Sun at midnight. It is low. At 70° N it stands 3.44 degrees up on June 21, 2026, and at the Arctic Circle it is at the horizon.
• Thinking only the pole has it. Every place north of the circle gets a stretch of 24-hour sunlight, and the stretch gets longer toward the pole.
• Expecting one single day at the circle. The 2026 table gives 29 days at 66.5° N, and the National Weather Service says early June to early July.
• Treating 66.5° as a razor-sharp number. Official pages give 66°32′, 66°33′ and 66°34′, and NOAA says the line moves slightly over time.
• Mixing up the two circles. NOAA's education page says the Antarctic Circle has the same effect at the opposite solstice.
• Staring at the glowing Sun. NASA's eclipse viewing safety page says it is not safe to look directly at the Sun without specialized eye protection for solar viewing. The only exception it lists is the brief totality of a total solar eclipse, so a low midnight Sun is not an exception. Enjoy the light, not the disk.

Try it in the instrument

Open the Orbit Dial and set the sky to the Arctic Circle, the lowest latitude where the Sun stays up all day on the June solstice. The dial takes a date in 2026 and a latitude, then shows the Sun's height at noon and the length of the day.

Set the date to the June solstice, June 21, 2026, which the Naval Observatory lists at 08:24 Universal Time. Then raise the latitude until the day-length readout reaches 24 hours. The target is about 66.5° N, which is 90 degrees minus the tilt.

Use official numbers to see why the edge matters. At 60° N the longest day is 18 h 53 min, according to the Naval Observatory. At 66.5° N the table shows 24 hours. At that latitude the Sun is about 47 degrees high at noon and at the horizon at midnight, because the Naval Observatory's computed heights are 46.94 and −0.06 degrees. The two readings differ by about 47 degrees, twice the tilt.

The dial is a simplified model, so it may place the edge a fraction of a degree away from the official line. The relation is the lesson: the circle is where the Sun's lowest point reaches the horizon, and the tilt sets it. For the full picture of hours by latitude and date, read the guide on day length.

Questions people ask

What is the latitude of the Arctic Circle?

About 66°33′ N, according to the National Snow and Ice Data Center, or roughly 66.5° N. It equals 90 degrees minus the tilt of 23.4 degrees, and it shifts slightly over time.

Does the Sun really shine at midnight?

Yes, north of the Arctic Circle around the June solstice, but it is low. At 70° N it is 3.44 degrees above the horizon at local midnight on June 21, 2026, in the Naval Observatory's data.

How long does the midnight Sun last at the North Pole?

About six months, from near the March equinox to just after the September equinox, according to the National Weather Service. NOAA puts the Sun's rise near March 21 and its set near September 21.

Can you see the midnight Sun in the United States?

Yes. In the Naval Observatory's 2026 table, the Sun stays up for 24 hours a day from May 11 to August 1 at 71.3° N. The National Weather Service describes similar light at Barrow, Alaska, slightly north of 71° N.

Is there a midnight Sun in the south?

Yes. NOAA's education page says the Antarctic Circle has the same effect at the opposite solstice, which falls in December.

Sources

• arctic circle, National Snow and Ice Data Center (NSIDC). https://nsidc.org/learn/cryosphere-glossary/arctic-circle. Opened November 10, 2026.
• Arctic Zone: Daylight, Darkness and Changing of the Seasons at the North Pole, NOAA Pacific Marine Environmental Laboratory. https://www.pmel.noaa.gov/arctic-zone/gallery_np_seasons.html. Opened November 10, 2026.
• Arctic FAQ - Frequently Asked Questions about the Arctic, NOAA Pacific Marine Environmental Laboratory. https://www.pmel.noaa.gov/arctic-zone/faq.html. Opened November 10, 2026.
• What Causes the Seasons?, National Weather Service, Sioux Falls. https://www.weather.gov/fsd/season. Opened November 10, 2026.
• What Is a Solstice?, NOAA NESDIS. https://www.nesdis.noaa.gov/about/k-12-education/optical-phenomena/what-solstice. Opened November 10, 2026.
• Helio and You: Learning About the Sun in the Far North, NASA Science. https://science.nasa.gov/helio-and-you-learning-about-the-sun-in-the-far-north/. Opened November 10, 2026.
• Facts About Earth, NASA Science. https://science.nasa.gov/earth/facts/. Opened November 10, 2026.
• Navigation--lesson plan #8, NASA Goddard Space Flight Center (From Stargazers to Starships). https://pwg.gsfc.nasa.gov/stargaze/ILnavigat.htm. Opened November 10, 2026.
• Duration of Daylight/Darkness Table for One Year, U.S. Naval Observatory. https://aa.usno.navy.mil/data/Dur_OneYear. Opened November 10, 2026.
• Comparative Lengths of Days and Nights, U.S. Naval Observatory. https://aa.usno.navy.mil/faq/longest_day. Opened November 10, 2026.
• Earth's Seasons - Equinoxes, Solstices, Perihelion, and Aphelion, U.S. Naval Observatory. https://aa.usno.navy.mil/data/Earth_Seasons. Opened November 10, 2026.
• Application Programming Interface Documentation, U.S. Naval Observatory. https://aa.usno.navy.mil/data/api. Opened November 10, 2026.
• Eclipse Viewing Safety, NASA Science. https://science.nasa.gov/eclipses/safety/. Opened November 10, 2026.

We opened each source ourselves on the date shown. The drawings are our own and were checked against the numbers in these sources.

Read next

• Earth’s Axial TiltEarth's axis leans about 23.4 degrees from the perpendicular to its orbit.
• Summer SolsticeAt the June solstice, Earth's axis leans the Northern Hemisphere as far toward the Sun as it ever goes, so the noon Sun stands highest there.