Summer Solstice 2025: The Longest Day of the Year Has Arrived
June 20, 2025, at 10:42 p.m. EDT marks a celestial milestone—the summer solstice—ushering in the official start of astronomical summer in the Northern Hemisphere. For skywatchers, sun-chasers, and daylight lovers, this is the year’s longest day. It offers more sunshine than any other.
What Is the Summer Solstice?
The summer solstice occurs when the sun reaches its northernmost point relative to Earth’s celestial equator—an imaginary extension of Earth’s equator into space. It happens thanks to Earth’s 23.5-degree axial tilt, a permanent angle created billions of years ago when a Mars-sized object collided with our planet, ultimately leading to the formation of the moon.
That same tilt is responsible for Earth’s seasons, equinoxes, and solstices, all of which have been celebrated by ancient civilizations around the world. Monuments like Stonehenge in England and Chichén Itzá in Mexico were designed to align with the solstice sun, marking its annual return with remarkable precision.
How Much Daylight Do We Get?
In cities like New York, the sun will stay above the horizon for more than 15 hours today. This extra daylight reaches its annual peak on the summer solstice before slowly beginning to shorten again each day until the winter solstice in December.
Curious about how long the sun will shine where you live? Tools like TimeandDate.com’s Daylight Tracker let you measure sunrise and sunset times globally.
A Time of Duality Across the Globe
While those in the Northern Hemisphere are soaking up the year’s longest day, people in the Southern Hemisphere are experiencing the winter solstice, their shortest day of the year. It’s a natural reminder of Earth’s elegant balance, as the planet’s tilt affects global light and temperature patterns.
What It Means for Stargazers
With extended sunlight, the summer solstice can be a tough time for amateur astronomers looking for dark skies. Still, summer skies are home to bright asterisms, such as the Summer Triangle, and deep-sky objects perfect for late-night viewing once the sun finally sets.
More…
- https://www.space.com/stargazing/summer-solstice-2025-is-here-today-marks-the-longest-day-of-the-year-for-the-northern-hemisphere
- https://www.dailymail.co.uk/news/article-14834107/Crowds-Summer-Solstice-Stonehenge-25-000-sunrise-centre-ancient-stone.html
- https://www.forbes.com/sites/jamiecartereurope/2025/06/20/summer-solstice-2025-the-exact-time-for-every-us-state
