Summer Solstice 2023: The First Day of Summer and the Longest Day

One of the hemispheres of the Earth experiences its summer solstice when it is inclined closest to the Sun and receives the most daylight.

The following summer solstice will occur in the Northern Hemisphere on June 21, 2023. On December 22, 2023, it will take place in the Southern Hemisphere.

Astronomically, summer officially begins on the summer solstice. We have the longest day and shortest night on this day. This event has dozens of celebrations associated with it all around the world.

Imagine the Earth is in orbit around the Sun. As we all know, the Earth rotates both around the Sun and on its own axis, which is represented by a hypothetical straight line passing across the Earth from North to South.

This axis is inclined at around 23.5° and is not perpendicular to the Earth’s orbital plane. Because of this, the North and South poles incline towards the Sun at various degrees throughout the year

Thus, in that hemisphere, the summer solstice occurs when one of the Earth’s hemispheres reaches its maximum tilt towards the Sun. The greatest sunlight falls onto it on this day, which results in the longest day of the year there.

The summer solstice marks the start of summer. It will take place for the Northern Hemisphere on June 21, 2023.

The seasons are reversed in the southern hemisphere. The start of the season there will be on December 22, 2023. (By the way, to avoid misunderstanding, astronomers prefer to say June or December solstices. But what takes place on June 1? That marks the start of summer, isn’t it? That depends on how you view it, I suppose. According to astronomy, a new season can start on any planet, not just the Earth, on a solstice or an equinox. For thousands of years, our ancestors employed these natural events as timekeepers; they served as the foundation for the celestial calendar. However, because the solstices and equinoxes occur at different times each year, it is challenging to compare seasonal data because the length of the seasons fluctuates from 89 to 93 days.

This problem was solved by the creation of meteorological seasons, which divide the year into three-month chunks based on patterns of annual temperature. Since these seasons are more reliable and better align with our civil calendar, it is much simpler to convert monthly numbers into seasonal ones. Conveniently, both of them are excellent for a variety of uses, including commerce and agriculture.

Note that the dates here are provided for Greenwich Mean Time (GMT). In your local time zone, the dates can vary.

In the Northern Hemisphere, the summer solstice usually occurs on June 20 or 21. Rarely it can occur on June 22, but that won’t happen in the 21st century. The next summer solstice on this date will occur in 2203.

In the Southern Hemisphere, the summer solstice most of the time happens on December 21 or 22; it can also rarely fall on December 20 or 23. In this century, only five solstices occur on December 20. The next solstice on December 23 will occur in 2303.

2023: June 21, 14:58 GMT (10:58 a.m. EDT)

2024: June 20, 20:51 GMT (4:51 p.m. EDT)

2025: June 21, 02:42 GMT (June 20, 10:42 p.m. EDT)

2026: June 21, 08:25 GMT (4:25 a.m. EDT)

2027: June 21, 14:11 GMT (10:11 a.m. EDT)

2023: December 22, 03:28 GMT

2024: December 21, 09:20 GMT

2025: December 21, 15:03 GMT

2026: December 21, 20:50 GMT

2027: December 22, 02:42 GMT

After the summer solstice, the days get shorter. The most daylight is available to individuals on this day. Then, as the days get shorter and shorter, the lengths of day and night are about equal at the autumnal equinox.

The length of the summer solstice is longer in places closer to the equator because there are bigger seasonal variations in day length. The longest day in 2023 will be 19 hours and 09 minutes long in Canada’s far north city of Whitehorse. The longest day will be 12 hours and 23 minutes long in Bogota, Colombia, which is close to the equator.

When the Sun goes down, places within the polar rings experience Midnight Sun or polar day for a few days or months. Sun does not set at all.

Every planet in the Solar System experiences seasons because they all have an axial tilt. Only Mercury has such a small axial tilt that we can’t even tell when one season ends and the next one begins. Let’s take a look at how long summer lasts on other planets.

Due to its great axial tilt of 98° (the planet essentially rotates on its side with respect to the plane of the Solar System), Uranus has the most fascinating seasons of all the planets. Imagine having a summer day that lasts for one-fourth of your entire life! This is the situation with Uranus, whose summer hemisphere has a 21-year continuous face-off with the Sun. The night lasts for 21 years on the other (winter) side of this strange planet. But things change in the spring and the autumn. Sunlight reaches the planet’s equatorial zone around the equinoxes. Every 17 hours and 14 minutes, Uranus turns on its axis. This indicates that a large portion of the world has a somewhat typical (17-hour) day/night cycle.

People assemble around Stonehenge, dance around a maypole, decorate homes with greenery, light massive bonfires, and other activities to mark the beginning of summer. We urge you to go outside and see the night sky since we are astronomy enthusiasts! On June 21, 2023, these sights can be seen near the solstice:

On June 17, Saturn, Neptune, Jupiter, Uranus, and Mercury will be in a broad morning alignment. A 93-degree sky sector will be visible for the planets.

Moon will pass close to Mars (mag. 1.7) in the constellation Leo and Venus (mag. -4.4) in the constellation Cancer on June 22.

If you’re in the Northern Hemisphere, on any cloudless night, take the opportunity to explore the summer constellations — Cygnus, Lyra, Aquila. If you live in the Southern Hemisphere, June 21 is the winter solstice day for you. The winter constellations for the southern latitudes include Scorpius, Sagittarius, and Ophiuchus.

To find all the listed objects and more, use the sky guides Star Walk 2 or Sky Tonight. All you need to do is to launch an app and point your device at the sky — you’ll see an interactive sky map on your screen!

You can also start celebrating right now by taking the solstices and equinoxes quiz. Don’t wait any longer to see if you’re a true astronomy expert!