The moment of the summer solstice in 2025 will take place on Saturday, June 20-21, at 2:41 a.m. GMT (9:41 p.m.EST).
Although most people think of the June solstice as June 21, it can occur any day between June 20 and June 22, depending on the time zone. The June 22 solstice is rare; the last one was in 1975, and the next one will be in 2203.
Image Credit & Copyright: Marcella Giulia Pace & Giuseppe De Donà
The difference in the dates of the equinoxes and solstices arises from the discrepancy between the calendar and tropical years (the time it takes for the Earth to complete a full revolution around the Sun, approximately 365.242199 days). As a result, the solstice occurs about 6 hours later each year, until the accumulated difference shifts the event to the next date.
To align the calendar with the tropical year, a leap day is introduced about once every four years. After that, the dates of the equinoxes and solstices are shifted back to an earlier date. The solstice is also influenced by factors such as changes in the length of the tropical year, the Earth’s orbital movements, and the “wobble” of the Earth’s axis (precession).
Read more about what the summer solstice is and how long the longest day of the year will last in the article at the link.
