The summer solstice, recognized as the year’s longest day in the Northern Hemisphere, is set to occur on June 20 this year in North America. Traditionally, each summer solstice is commemorated with festive gatherings at Stonehenge in England, where participants remain awake throughout the night to witness the dawn of the longest day, as reported by Live Science.
However, this year presents a unique circumstance: the summer solstice in England will fall on a different date than that in North America, a disparity attributable to time zone variations. In 2025, the summer solstice in the Northern Hemisphere is slated to take place at 02:42 UTC on Saturday, June 21. Consequently, this event will transpire at 10:42 PM Eastern Daylight Time on Friday, June 20, and at 3:41 AM British Summer Time on Saturday, June 21.
The term “solstice” originates from Latin, where “sol” signifies “sun” and “stice” means “to stand still.” This etymology is fitting, as it appears that the sun reaches its most northerly and southerly positions on the horizon on two distinct occasions each year: between December 20 and December 22, and between June 20 and June 22.
From an astronomical perspective, the sun is positioned at its highest altitude in the sky during midday on the day of the summer solstice in the Northern Hemisphere. This implies that the sun rises at its farthest northeast location and sets at its farthest northwest position.
Conversely, in the Southern Hemisphere, the June solstice corresponds to the winter solstice. When the sun attains its maximum elevation in the Northern Hemisphere, it is at its minimum elevation in the Southern Hemisphere. This phenomenon is reversed during the December solstice, which represents the longest day and shortest night in the Southern Hemisphere. During the equinoxes, occurring between March 19 and 21 and September 21 and 24, the sun rises and sets directly in the east and west, respectively, across the globe.
The occurrence of solstices and equinoxes is a result of Earth’s axial tilt of 23.5 degrees in relation to its orbital plane around the sun, leading to the changing seasons. During the summer solstice, the Northern Hemisphere is tilted toward the sun, resulting in an extended duration of sunlight, which marks this day as the lengthiest of the year.
Despite the logical assumption that the summer solstice would also represent the warmest day of the year, a slight seasonal lag occurs due to the time required for Earth’s predominantly aqueous surface to absorb and release thermal energy, as noted by the Royal Meteorological Society. At the North Pole, there is continuous sunlight during the summer solstice, while the South Pole experiences perpetual darkness.
