Summer Solstice: What To Know About The Longest Day Of 2025 And How To Celebrate It

Summer isn’t so much a defined season as it is a state of mind — a feeling of well-being, relation and enjoyment of activities that only happen during warm weather.

But for those looking for an official start date, the summer solstice on Friday, June 20, has long been regarded as the official start of the season. By the astronomical calendar, summer ends on Sept. 22 with the autumnal equinox. Meteorological summer — a fixed period of June, July and August — is based on the annual temperature cycle. Meteorological fall begins Sept. 1.

The sun travels its longest path through the sky on the day of the summer solstice, which occurs the exact moment it reaches its highest and northernmost points in the sky. In 2025, that’s at 10:42 p.m. Eastern Daylight Time.

The Longest Day

The summer solstice is always the longest day of the year.

The closer a person lives to the North Pole, the longer the day will be. At the North Pole itself, the sun won’t set at all on the Solstice. And at the South Pole, where the June solstice marks the beginning of astronomical winter, the sun won’t rise.

In Point Barrow, Alaska, the northernmost point of land in the United States, the sun won’t set at all. In the northernmost point in the continental U.S., Angle Inlet, Minnesota, will have about 16 hours of daylight. (As an aside, this inlet jutting into Canada is separated from the rest of Minnesota by Lake of the Woods and is accessible only by land through Manitoba and Ontario, Canada, due to an 18th-century surveying error.)

Key West, Florida, the southernmost point of the continental U.S., will have about 13 hours, 39 minutes and 38 seconds of daylight on the solstice. In all 50 states, Ka Lae on the island of Hawaii is the southernmost point. Daylight will last about 13 hours and 12 seconds.

What Are Solstices And Equinoxes?

As LiveScience explains “Solstices and equinoxes happen because Earth's axis of rotation is tilted 23.5 degrees from the plane of its orbit around the sun, which causes the seasons. On the summer solstice, the Northern Hemisphere is tilted toward the sun, so it receives the full glare of the sun's rays for the longest time and the day is therefore the longest.”

The arrival of the solstice doesn’t necessarily translate to high temperatures. The seasonal lag in the arrival of the hottest weather of the year is explained by the fact that our mostly watery planet needs time to absorb the heat, according to the Royal Meteorological Society.

How Is The Summer Solstice Celebrated?

The biggest solstice party of the year happens at Stonehenge, perhaps the world’s most famous prehistoric monument. The henge monument was built around 5,000 years ago, the stone circle was erected in the Neolithic around 2500 B.C. and burial mounds were built nearby in the early Bronze Age.

A prevailing theory about Stonehenge is the monument was built to track and mark astronomical events like solstices and moon cycles. Stonehenge's central axis aligns with the sunrise at the summer solstice and the sunset at the winter solstice, framing the rising and setting sun during the longest and shortest days of the year.

In Sweden, people dance around the maypole. In Ukraine and parts of Eastern Europe, the solstice coincides with Ivan Kupala Night, a celebration marked by dancing, the laying of flowered wreaths on the water and gatherings around bonfires. In India, mass yoga sessions are held throughout the country.

In Puerto Rico, a mass plunge into the ocean marks the solstice. During Iceland’s Jónsmessa celebration, it is said cows can talk and elves interact with people during this time of positivity and goodness. Smithsonian magazine notes that “some Icelanders roll around naked in the morning dew to supposedly promote good health,” but they may also take advantage of the midnight sun and hike over the 15-mile stretch between the glaciers Eyjafjallajökull and Mýrdalsjökull.

The United States has its share of summer solstice celebrations, with multiple cities holding parades and festivals. One of the largest is a solstice parade and free festival in Santa Barbara, California. A baseball game is played under the midnight sun in Fairbanks, Alaska.

• Related: How DOGE Cuts Could Affect Your Summer Vacation

Look Up And Celebrate Summer

The summer solstice offers a short window to see electric blue noctilucent clouds. The highest clouds in Earth's atmosphere float about 50 miles above our planet's surface near the edge of space, which starts at an altitude of 62 miles.

These clouds, formed by ice crystals or dust from meteor smoke, are only visible for a few weeks between the end of May and the start of August. Because they’re so high in the sky, noctilucent clouds are illuminated by the sun long after it has gone to bed on Earth, and appear as blue-white swirls, curls and tendrils that shimmer in the sky.

As you’re filling out your summer calendar, block out a few dates for the summer meteor showers. The Delta Aquariids, Alpha Capricornids and the always-anticipated Perseids all start in July. The Perseids peak in mid-August. Famous for producing numerous fireballs, the Perseids run July 14-Sept. 1 and produce up to 100 shooting stars an hour at the peak.

• Related: 2025 Guide To Meteor Showers And Other Celestial Events

And, who knows, you may get a chance to see the aurora borealis, or northern lights. The sun remains in overdrive after having reached “solar maximum” in its 11-year cycle. The northern lights have already dipped far south of the Arctic range several times this year, and more activity is expected.

Activity during the current Solar Cycle 25 has surprised space weather scientists and forecasters. It is the most active on record, and they’re not quite sure why.

“It’s one of the many mysteries to unravel,” space weather forecaster Shawn Dahl explained in a briefing with reporters in October. He and others expect more northern lights displays outside the Arctic range in 2025, and perhaps into 2026.

• Related: Get Ready For Killer Heat, New Report Warns