Every year on the summer season solstice, revelers at Stonehenge in England keep up all night time to have fun the daybreak of the longest day of the yr within the Northern Hemisphere, with many pictures streamed dwell.
However this yr, there is a twist: The summer season solstice there’ll happen on a unique day than the solstice in North America, as a consequence of time zone variations. So when is the summer season solstice in 2025, and what is the science behind it?
This yr, the summer season solstice within the Northern Hemisphere happens at 02:42 UTC on Saturday, June 21, 2025. Meaning it is at 10:42 p.m. EDT on Friday, June 20 and at 3:41 a.m. BST on Saturday, June 21.
The occasion’s title is instructive: “Sol” means “solar” in Latin, whereas “stice” means to face nonetheless. That is precisely what seems to occur on two days every year — one between Dec. 20 and Dec. 22, and the opposite between June 20 and June 22 — when the solar rises and units at its most northerly or southerly factors on the horizon.
For those who take into account the seasons and the solar’s place within the sky, that checks out: The solar reaches its highest level within the noon sky within the Northern Hemisphere on the day of the summer season solstice, which implies it have to be rising at its farthest northeast and setting at its farthest northwest.
Exactly the alternative is occurring within the Southern Hemisphere, the place the June solstice is the winter solstice. When the solar is highest within the Northern Hemisphere’s daytime sky, it is the lowest within the Southern Hemisphere’s daytime sky. The state of affairs is reversed for the December solstice, the longest day and the shortest night time within the Southern Hemisphere. On the equinoxes (“equi” and “nox,” that means equal night time), between March 19 and 21 and between Sept. 21 and 24, the solar seems to rise and set due east and west, respectively, from in all places on Earth.
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Solstices and equinoxes occur as a result of Earth’s axis of rotation is tilted 23.5 levels from the airplane of its orbit across the solar, which causes the seasons. On the summer season solstice, the Northern Hemisphere is tilted towards the solar, so it receives the complete glare of the solar’s rays for the longest time and the day is due to this fact the longest.
Following this logic, it could appear that the summer season solstice must also be the warmest day of the yr. Nevertheless, there is a slight seasonal lag as a result of our largely watery planet takes time to soak up the warmth, in accordance with the Royal Meteorological Society. On the North Pole, the solar doesn’t set on the summer season solstice, whereas on the South Pole, the solar doesn’t rise.