On June 21, the Northern Hemisphere will experience the longest day of the year, marking the official start of the summer season.

This astronomical occurrence is a result of Earth's axial tilt, which reaches its maximum inclination on this day. As a consequence, the sun attains its highest position in the sky, leading to an extended duration of daylight. It is a special time when people can enjoy the extended sunlight and make the most of the summer season's warmth and outdoor activities.

It nearly always falls on June 21. However, in some time zones, it might fall on June 20 or June 22.

What is the summer solstice?

The summer solstice, when the sun is directly above the Tropic of Cancer, brings about the longest daylight hours of the year. This astronomical event leads to unique phenomena in countries along or near the Tropic of Cancer, such as Mexico, northern Africa, the Middle East, India, and China.

In Mexico, the ancient Mayan ruins of Chichén Itzá showcase architectural designs that align with the sun during solstices. During the summer solstice, an intriguing event called the "El Castillo" or "The Temple of Kukulcan" occurs, where sunlight creates the illusion of a descending snake on the temple's stairs.

Northern Africa, including Egypt, features ancient structures like the Great Pyramids of Giza, which align with astronomical events, including the summer solstice. The Middle East hosts several culturally and historically significant sites associated with the summer solstice. Stonehenge in the United Kingdom, though not situated directly along the Tropic of Cancer, still holds astronomical significance.

Regions located closer to the poles, such as the Arctic and Antarctic, undergo a remarkable change in daylight hours during the summer solstice. This change often leads to the phenomenon known as the "midnight sun," where the sun remains visible throughout the night.

summer solstice
Revellers welcome in the Summer Solstice at Stonehenge stone circle in southwest Britain, June 21, 2018. REUTERS/Toby Melville

Summer solstice quotes

1. Summer is the annual permission slip to be lazy. To do nothing and have it count for something. To lie in the grass and count the stars. To sit on a branch and study the clouds." ― Regina Brett

2. "Summer's lease hath all too short a date." ― William Shakespeare

3. "Summer is the time when one sheds one's tensions with one's clothes, and the right kind of day is jeweled balm for the battered spirit. A few of those days and you can become drunk with the belief that all's right with the world." ― Ada Louise Huxtable

4. "Oh, the summer night, Has a smile of light, And she sits on a sapphire throne." ― Bryan Procter

5. "Summer, after all, is a time when wonderful things can happen to quiet people." ― Deb Caletti