While the Northern Hemisphere experiences its longest day, the Southern Hemisphere sees its shortest.
WASHINGTON — The summer solstice, the official start of summer, is on Friday, June 20.
For those north of the equator, the solstice marks the longest day and the shortest night of the year. The Earth spins on a tilt as it revolves around the sun. The summer solstice occurs for Earth’s upper half when the Northern Hemisphere is tilted most closely toward the sun.
Around the same time, those south of the equator will see the shortest day of the year, known as the winter solstice.
The Southern Hemisphere will see less than 12 hours of daylight while the northern half of the Earth basks in daylight longer than 12 hours, according to NASA.
After the solstice, days will gradually shorten until the winter solstice in December.
What time is the summer solstice 2025?
The summer solstice occurs on Friday, June 20, 2025, at 10:42 P.M. EDT., according to TimeandDate.
While it’s often believed that the summer solstice is an event that spans an entire calendar day, the solstice actually lasts just a moment, according to the Old Farmer’s Almanac.
When does summer start?
The summer solstice marks the beginning of astronomical summer each year, typically falling between June 20 and June 22.
In meteorology, the official start of the summer season is June 1, marking the beginning of the three warmest months of the year in the northern hemisphere.
What’s the difference between an astronomical and a meteorological season?
Astronomical seasons are determined by the Earth’s tilt and the sun’s alignment over the equator, according to the National Centers for Environmental Information. These seasons are split into summer and winter solstices and fall and spring equinoxes.
Additionally, the start dates for solstices and equinoxes vary depending on if it’s a leap year.
Meteorological seasons are split into groups of three months based on annual temperature cycles, the NCEI says. These seasons are more closely aligned to our monthly calendar than astronomical seasons.
What causes the summer solstice?
Solstices and seasons happen because of the Earth’s tilt. You can think of Earth’s axis as an imaginary pole through the center of the planet from top to bottom, NASA explains. Earth spins around this pole, making one turn each day and causing day and night.
That axis is tilted about 23.5 degrees. The North Pole is tilted toward the sun in June, resulting in more direct sunlight and warmer temperatures for its hemisphere.