Summer Solstice 2025: Why June 21 will be longest day, how it's celebrated around world

As summer begins in the Northern Hemisphere, June 21, 2025, brings with it the longest day and the shortest night of the year. This event, known as the summer solstice, happens when the Earth is tilted closest to the Sun, making the Sun appear at its highest point in the sky over the Tropic of Cancer. The summer solstice will officially occur at 8:12 am IST on Saturday, June 21. On this day, most places in the Northern Hemisphere, including countries like India, the United States, and those across Europe, will enjoy the longest hours of daylight for the entire year. In fact, places near the North Pole will experience 24 hours of daylight, a period known as the midnight sun.

Why Is June 21 the Longest Day?

The exact date of the solstice can vary slightly each year because Earth’s orbit around the Sun takes around 365.25 days. That extra quarter day is why we have leap years every four years, to help keep the calendar in line with Earth’s movements. The main reason behind the solstice is Earth’s 23.5-degree tilt on its axis. This tilt causes different parts of the planet to receive varying amounts of sunlight throughout the year, creating our seasons. On June 21, the Northern Hemisphere leans most directly toward the Sun, so the sunlight lasts longer and falls more directly, leading to the longest day.

At the same time, the Southern Hemisphere is tilted away from the Sun. So, for places like Australia or Argentina, June 21 marks the shortest day and longest night. In regions near the South Pole, such as those inside the Antarctic Circle, the Sun doesn’t rise at all, a period called polar night.

A Day of Celebration and Reflection

The summer solstice has been important to people around the world for thousands of years. In England, many gather at Stonehenge to watch the sunrise through the ancient stones—a tradition believed to date back to prehistoric times. In India, the day is closely followed by International Yoga Day on June 21, promoting peace, wellness, and balance.

While the solstice marks the start of astronomical summer, it also reminds us that from June 22 onwards, the days will slowly begin to get shorter again. It’s a time to enjoy the light, connect with nature, and reflect on the constant movement of our planet.