Today is the Summer Solstice … Local Time & Date in Chicago, Wednesday, June 21, 2023 at 9:57 am CDT start of astronomical summer and the longest day of the year
The summer solstice: When is it and when does it occur?
By Daisy Dobrijevic
last updated about 14 hours ago
The summer solstice is celebrated around the world.
The summer solstice marks the official start of astronomical summer and the longest day of the year. It occurs when one of Earth’s poles is tilted toward the sun at its most extreme angle, and due to Earth’s tilt, this happens twice a year. In the Northern Hemisphere, the summer solstice falls in June (while the Southern Hemisphere experiences the winter solstice), and in the Southern Hemisphere, it falls in December (while the Northern Hemisphere experiences the winter solstice).
The next summer solstice for the Northern Hemisphere will occur on June 21, 2023, and the next summer solstice for the Southern Hemisphere will occur on Dec. 22, 2023.
The summer solstice and subsequent longest day of the year are celebrated by many cultures around the world with numerous traditions, holidays and festivals. From sunrise gatherings to midsummer festivals, summer solstice celebrations certainly blow the winter cobwebs away.
Joe Rao is Space.com’s skywatching columnist, as well as a veteran meteorologist and eclipse chaser who also serves as an instructor and guest lecturer at New York’s Hayden Planetarium.
What is the summer solstice?
It marks that moment when the sun reaches that point when it is positioned farthest north — 23.5 degrees from the celestial equator. This point on the Earth is known as the Tropic of Cancer. The word solstice literally means “sun standing still.” It is derived from combining the Latin words sol for “sun” and sistere for “To Stand Still”.
For the previous six months, the sun has appeared to migrate on a northerly course in the sky. At the moment of the solstice, that motion stops and then the sun will begin to move south. A motion that will continue for six months until the sun drops to its lowest point below the equator and then stop — another solstice point — marking the beginning of winter.
When does the summer solstice occur?
During the 21st century, the dates for the occurrence of the solstice can fall either on June 20th or 21st.
How many hours of daylight do we get on the summer solstice?
In the Northern Hemisphere, the length of daylight varies depending on the latitude. At the equator, the time from sunrise to sunset is about 12 hours. At temperate or mid-northern latitudes (approximately 40 degrees north) the length of daylight lasts about 15 hours. And for those who are north of the Arctic Circle (66.5 degrees north) the sun remains above the horizon for 24 hours.
Is summer solstice the first day of summer?
For most of the world, this is true. But for other parts of the world, the solstice is looked upon not as the start of summer, but rather as midsummer. If, for example, you were to pay a visit to Sweden or Norway at this time of year, you would find the local inhabitants celebrating a local holiday known as Midsummer’s Day, which by ancient custom falls on June 24, a day also linked with the name of St. John the Baptist. At night, fires are lit in the mountains in other parts of Europe. In northern Scandinavia, above the Arctic Circle, the phenomenon of the midnight sun at solstice time is a seasonal clock that seems to divide summer, if not the entire year into two distinct parts. It is that time of the year that the sun, having spent the previous six months plodding steadily northward has reached the pinnacle of its migration.
What causes the summer solstice?
We have Earth’s tilt to thank for the seasons, and without it both hemispheres would receive equal light throughout the year.
As Earth orbits the sun, the axis of rotation of Earth is slightly tilted at 23.44°.1 according to the Royal Museums Greenwich. This means that as Earth orbits the sun, the Northern Hemisphere is tilted towards the sun during one half of the year. During the other half of the year, the Southern Hemisphere tilts towards it.
When the Northern or Southern Hemisphere is most tilted towards the sun, it experiences the summer solstice; when it is most tilted away, it experiences the winter solstice.
The solstices also do not land on the same calendar day every year because the astronomical year is 365.25 days long. As such, the summer solstice for the Northern Hemisphere — also known as the June solstice — currently shifts between June 20, 21 and 22. The summer solstice does, however, occur at the same time for every country independently of which side of Earth is facing the sun. This means the exact moment of summer solstice can occur in the middle of the night for some people and the middle of the day for others.
What is the meaning of solstice?
The word solstice is derived from the Latin word solstitium which translates to “sun stands still.” This is due to the apparent movement of the sun to the north or south stops before changing direction, according to Dictionary.com.
While the sun always rises in the east and sets in the west, it appears higher or lower in the sky throughout the year, depending on the season. Around the solstices, the sun reaches its apparent highest and lowest point in the sky. These correspond to midsummer and midwinter respectively, which are the turning points in the sun’s journey.
Once the sun reaches its zenith at the summer solstice, it will begin its journey toward the horizon, culminating in the winter solstice at its lowest point. In the weeks before these solstice turning points, the sun appears to move very little, earning it the name “sun standstill.”
If you were to map the sun’s midday position every day for a year, it would make a lopsided figure eight, called an analemma. The point at which the curves of the figure eight intersect is the equinox, which is when day and night are roughly equal in length.
Artist’s illustration of an analemma in the sky. Each point of light demonstrates a “snapshot” image of the sun’s position in the sky. When displayed together all the points of light look like a lopsided figure of eight stretching across the blue sky.
Summer solstice 2023 will occur on June 21 at 10:58 a.m. EDT (1458 GMT) for the Northern Hemisphere and on Dec. 22, 2023, for the Southern Hemisphere. To determine how many hours of daylight you’ll receive during the summer solstice, you can use The Farmer’s Almanac Sunrise and Sunset Calculator.
Summer solstice celebrations
Humans have been observing the sun’s position in the sky for thousands of years, and monuments such as Stonehenge in England, Karnak in Egypt, and Chankillo in Peru stand as a testament to our fascination with our nearest star. Solstices have also influenced many traditions and celebrations around the world.
At Stonehenge in the U.K., the sun rises behind the ancient entrance to a stone circle and “the sunlight is channeled into the center of the monument,” the BBC reported. Researchers believe that solstices have been celebrated at Stonehenge for thousands of years. The stone circle is particularly important to pagans and druids.
According to some ancient Greek calendars, the summer solstice heralded the beginning of the new year and marked the one-month countdown to the start of the Olympic Games, according to St Neots Museum in the U.K.
In Sweden, midsummer celebrations rooted in paganism are the highlight of the year for many. The weekend surrounding the solstice is filled with food, drink and plenty of singing, according to Lonely Planet. Flower-wreath-wearing revelers take part in maypole and folk dances such as the traditional “Små grodorna”.
In the U.S., some Native American tribes living in the plains and The Rocky Mountains perform a Sun Dance to celebrate the summer solstice. In Fairbanks, Alaska, a baseball game known as the “Midnight Sun Game” traditionally starts at 10:30 p.m and takes a brief pause close to midnight for everyone to sing the Alaska Flag Song.
In the Wiccan religion, people celebrate Yule at the winter solstice to herald the return of the sun and warmer months.
Additional resources
Explore the difference between the equinox and solstice with the UK Met Office. Learn how to make your own solstice and equinox “suntrack” season model with NASA and the Stanford Solar Center. Discover 11 interesting June solstice facts with Time and Date.
Bibliography
Bland, A. (2012, December 20). The best places to see and celebrate the Winter Solstice. Smithsonian Magazine. Retrieved September 26, 2022, from https://www.smithsonianmag.com/travel/the-best-places-to-see-and-celebrate-the-winter-solstice-169694017/
Chankillo Archaeoastronomical Complex. World Monuments Fund. (2021, July 1). Retrieved September 26, 2022, from https://www.wmf.org/project/chankillo-archaeoastronomical-complex
Midnight Sun Game. Alaska Goldpanners of Fairbanks – Pointstreak Sites. Retrieved September 26, 2022, from http://goldpanners.pointstreaksites.com/view/goldpanners/june-21-2023-midnight-sun-game-tickets-go-on-sale-in-november-2022-stay-tuned
National Institutes of Health. Cheyenne Indians at a sun dance, by Edward S. Curtis, circa 1910. U.S. National Library of Medicine. Retrieved September 26, 2022, from https://www.nlm.nih.gov/nativevoices/exhibition/healing-ways/medicine-ways/key-role-of-ceremony/images/ob1410.html
Why do we celebrate the summer solstice? St Neots Museum. Retrieved September 26, 2022, from https://www.stneotsmuseum.org.uk/articles/why-do-we-celebrate-the-summer-solstice/
Salisbury, V. (2020, June 18). Top 8 summer solstice celebrations from around the World – Lonely Planet. Lonely Planet. Retrieved September 26, 2022, from https://www.lonelyplanet.com/articles/summer-solstice-celebrations
Sunrise and Sunset Times today: The old farmer’s almanac. Almanac.com. Retrieved September 26, 2022, from https://www.almanac.com/astronomy/sun-rise-and-set
When is the summer solstice? Royal Museums Greenwich. Retrieved September 26, 2022, from https://www.rmg.co.uk/stories/topics/summer-solstice
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By Konstantin Bikos, Aparna Kher, and Graham Jones
There are two solstices every year: one in June and one in December. The June solstice marks the longest day north of the equator and the shortest day in the south.
Earth’s position in relation to the Sun’s rays at the June solstice.
The June solstice is the moment the Sun is directly above the Tropic of Cancer in the Northern Hemisphere. This is the northernmost latitude it reaches during the year. After the solstice, it begins moving south again.
11 facts about the June solstice
Solstice Local Time & Date
In Chicago, Illinois, USA: Wednesday, June 21, 2023 at 9:57 am CDT (Change location)
This corresponds to Wednesday, June 21, 2023 at 14:57 UTC.
Longest Day in the North
Since the Northern Hemisphere is tilted toward the Sun in June, it receives more sunlight during the course of a day. The North Pole’s tilt toward the Sun is greatest at the solstice, so this event marks the longest day of the year north of the equator.
This effect is greatest in locations that are farther away from the equator. In tropical areas, the longest day is just a little longer than 12 hours; in the temperate zone, it is significantly longer; and places within the Arctic Circle experience Midnight Sun or polar day, when the Sun does not set at night.
Shortest Day in the South
Conversely, the day of the June solstice is the shortest day of the year in the Southern Hemisphere. Here, too, the effect is greater the farther a location is away from the equator.
Places within the Antarctic Circle experience polar night, when the Sun does not rise at all.
Why Is It Called a “Solstice?”
During a year, the subsolar point—the spot on the Earth’s surface directly beneath the Sun—slowly moves along a north-south axis. Having reached its southernmost point at the December solstice, it stops and starts moving northward until it crosses the equator on the day of the March equinox. At the June solstice, which marks the northernmost point of its journey, it stops again to start its journey back toward the south.
This is how the solstices got their name: the term comes from the Latin words sol and sistere, meaning “Sun” and “to stand still”.
Initially, the naming arose from observations of how the Sun’s apparent path across the sky changes slightly from one day to the next, which is caused by the same process as the subsolar point’s movement described above.
In the months leading up to the June solstice, the position of sunrise and sunset creeps northward. On the day of the solstice, it reaches its northernmost point. After that, the daily path of the Sun across the sky begins to creep southward again.
The subsolar point moves north and south during the year because the Earth’s axis is tilted at an angle of about 23.4° in relation to the ecliptic, an imaginary plane created by Earth’s path around the Sun. In June, the Northern Hemisphere is tilted toward the Sun, and the subsolar point is north of the equator. As the Earth travels toward the opposite side of its orbit, which it reaches in December, the Southern Hemisphere gradually receives more sunlight, and the subsolar point travels south.
How do seasons work?
The June solstice marks the start of summer in the Northern Hemisphere and the start of winter in the Southern Hemisphere, according to one definition.
The longest day of the year is commonly associated with the earliest sunrise and latest sunset of the year. However, in most locations, the earliest sunrise happens a few days before the solstice, while the latest sunset occurs some days after it. Find out why
The June Solstice in the Calendar
Even though most people consider June 21 as the date of the June solstice, it can happen anytime between June 20 and June 22, depending on the time zone. June 22 solstices are rare—the last June 22 solstice took place in 1975, and there won’t be another one until 2203.
Note: All dates refer to Coordinated Universal Time (UTC). Local dates may vary depending on the time zone.
Why Does the Date Vary?
The date of the equinoxes and solstices varies because a year in our calendar does not exactly match the length of the tropical year—the time it takes the Earth to complete an orbit around the Sun.
Today’s Gregorian calendar has 365 days in a common year and 366 days in a leap year. However, our planet takes about 365.242199 days to orbit the Sun. This means that the timing of the equinoxes and solstices slowly drifts apart from the Gregorian calendar, and the solstice happens about 6 hours later each year. Eventually, the accumulated lag becomes so large that it falls on the following date.
To realign the calendar with the tropical year, a leap day is introduced (nearly) every four years. When this happens, the equinox and solstice dates shift back to the earlier date again.
Other factors influencing the timing of the equinoxes and solstices include variations in the length of a tropical year and in the orbital and daily rotational motion of the Earth, such as the “wobble” in the Earth’s axis (precession).
