You’ll hear it called the longest day, the start of summer, or even midsummer. But what is the solstice, really? And why does this one moment affect everything from ancient rituals to your evening sunlight?
What Is the Summer Solstice?
The word ‘solstice’ is derived from the Latin wordsolstitium, which means “Sun stands still.” This refers to how the Sun momentarily pauses in its apparent northward or southward movement before reversing direction.
It’s an event that happens twice a year, once in the Northern Hemisphere on June 19th, 20, 21,or 22, and once in the Southern Hemisphere on December 20, 21, 22, or 23, and each marks the longest day of the year in its respective half. Most of the time,
The Science Behind the Longest Day
The Earth is slightly tilted as it journeys around the Sun. When the northern half of the planet tilts toward the big, orange ball, the days get longer and we get summer—culminating in the longest day of the year. That point is when the Sun is on its longest and highest path across the sky, giving us the most hours of daylight from sunrise to sunset.
For most of us, it’s only a few seconds longer than the previous day, but it is the longest day nonetheless, and depending on your time zone, it might happen during the day, evening, or while you’re asleep.
In 2025, the Northern Hemisphere’s summer solstice falls on June 20 at exactly 10:42 p.m. Eastern time. That’s 3:42 a.m. GMT if you’re across the pond in the U.K.
But why doesn’t the solstice fall at the exact same time every year? Well, that’s because the Earth actually takes 365 and a quarter days to orbit the Sun. Those quarter-days add up, so we throw in an extra calendar day every four years, known as a leap year, to keep things on track.
Without those leap years, the seasons would drift out of sync with the calendar, and over time, Christmas would end up being a summer celebration. Solstices, on the other hand, follow the Earth’s orbit, not our calendar, so they go out of sync by six hours each year until the leap year resets, which is why they don’t occur at the same time annually.
Why the Days Get Longer—and Then Shorter Again
It may appear to us that the Sun is moving up and down the sky as winter turns into summer and back again. However, it is in fact our planet’s tilting and turning that creates this illusion. The tilt leans at about 23.4 degrees off-center (often rounded up to 23.5) and completely controls how much daylight we get throughout the year.
In summer, the Northern Hemisphere tilts toward the Sun, resulting in earlier sunrises and later sunsets. In winter, the Northern Hemisphere tilts away, so the Sun takes a lower, shorter path across the sky, resulting in less daylight.
The solstices mark the peak and lowest point of this apparent motion. In June, we hit the longest day in the Northern Hemisphere. In December, it’s the shortest. In the Southern Hemisphere, it’s the opposite way around. In between,the equinoxes show up—two points in the year when day and night are roughly equal.
How Daylight Varies Around the World
When the northern half of the planet tilts toward the Sun, the days stretch out. The farther north you are, the more extreme it gets. In fact, the Sun barely sets at all in summer near the Arctic Circle. That’s why places like Alaska can have weeks of nonstop daylight, which is the perfect time to enjoy nature or genuinely start considering the benefits ofa solar power station. When it tilts away, the days shrink, and if you’re in the extreme north during these months, the Sun barely rises.
If you live in temperate mid-latitude regions like much of the U.S. and Europe, your days get noticeably longer in summer and shorter in winter, but nothing compared to the extremes of the far north.
At the equator, there’s barely any change. Day and night pretty much stay the same length all year. Twelve hours of sunlight and twelve hours of darkness. This consistent daylight ensures temperatures remain stable year-round. But, instead of four seasons, most equatorial regions have just two—a wet and a dry.
How the Summer Solstice Is Celebrated Globally
The longest day has been honored for centuries, and nowhere is this more visible than at Stonehenge, England. It may keep its secrets close, but there’s no doubt this monument was built with the Sun in mind. Thousands of people gather there each year to watch the sunrise line up with the Heel Stone—just as it has done for thousands of years.
The summer solstice also holds deep spiritual meaning for Native American communities. The Plains tribes, particularly the Sioux, traditionally held sacred Sun Dance ceremonies around this time. This ritual involved days of dancing, fasting, and personal sacrifice, which served to renew the tribe’s connection to nature and the spiritual world. It’s still practiced by some tribes today, though usually privately within the community to protect its sanctity from external influences.
Other tribes mark the solstice differently. The Coast Salish in the Pacific Northwest, for example, take part in long-distance canoe journeys to bring communities together, strengthen intertribal connections, and celebrate cultural heritage.
Elsewhere, thousands of people roll out yoga mats in the middle of Manhattan to take part in the annual “Solstice in Times Square” event. In other parts of the world, you might see sunrise drum circles, outdoor feasts, and dance parties running right into the morning.
Is the Solstice the Start of Summer or Midsummer?
This question trips people up a lot. Some will tell you the solstice marks the start of summer, while others insist it’s midsummer.
Astronomically, the solstice marks the beginning of summer. Historically, many pre-Christian pagan cultures saw it differently. For them, summer started in early May, which made late June the middle of the season—hence the term “midsummer.” They considered the solstice to be the sun at the peak of its summer strength before beginning its decline into winter.
This ancient perspective lives on today through Midsummer’s Day, which falls on June 24, very close to the solstice. It combines those old pagan beliefs with Christian traditions, particularly St. John’s Day. Over time, people began to use the word midsummer to reference both Midsummer’s Day and the solstice. That’s why you’ll hear both terms thrown around at solstice events.
So is the solstice the start of summer, or is it midsummer? Astronomically, it’s the start. Culturally, it’s the middle, but most modern calendars go with the astronomical definition.
So, now you know—the longest day of the year isn’t just a ‘fun-fact’ moment; it’s a hardwired-into-the-way-our-planet-spins-through-space moment. It marks the peak of the Sun’s climb, the start of summer (depending on who you ask), and a turning point that people have marked for thousands of years.
The dates might shift slightly, the traditions may vary, and even the terminology gets muddled, but the solstice itself doesn’t change. It’s a fixed part of how the Earth moves. It’s not symbolic or poetic—it’s just plain old orbital mechanics.
