Summer begins with longest day and shortest night across Saudi Arabia

Dubai: At precisely 5:42 a.m. local time on Saturday, June 21, 2025, the sun stood directly above the Tropic of Cancer, signaling the arrival of the summer solstice across Saudi Arabia and the rest of the Northern Hemisphere.

Astronomers say this marks the beginning of summer in astronomical terms, a season that will last 93 days, 15 hours, and 37 minutes this year.

On this day, the sun rises from its northernmost point on the horizon and sets at its furthest northwestern point. It also traces its highest arc across the sky, particularly noticeable in regions north of the equator, and casts the shortest noontime shadows of the year.

Majid Abu Zahra, head of the Jeddah Astronomy Society, said that the solstice occurs when the Earth’s axial tilt reaches its maximum angle of 23.5 degrees toward the sun. "This causes the sun to appear at its most northerly point in the sky," he said, "resulting in the longest day and shortest night of the year for the Northern Hemisphere."

But while the solstice consistently occurs around June 21, the date can vary slightly, falling between June 20 and 22, due to the mismatch between the Gregorian calendar year (365 days) and the solar year (365.2422 days), as well as gravitational influences from the Moon and planets, and minor variations in Earth’s rotation. These shifts are periodically corrected by the addition of leap days.

Abu Zahra also highlighted the distinction between astronomical and meteorological summer. “While meteorologists define summer as the period from June 1 to August 31, astronomers define it from the summer solstice onward,” he said.

Interestingly, the solstice does not coincide with the hottest day of the year. Due to a phenomenon known as “seasonal lag,” the land, oceans, and atmosphere take time to absorb and re-radiate solar energy, meaning peak temperatures typically occur in July or August.

The summer solstice also holds historical significance. Abu Zahra noted that the ancient Greek scholar Eratosthenes famously used observations from the solstice to estimate the Earth's circumference with remarkable accuracy, relying solely on basic geometry and the difference in shadow lengths between two cities.

Following Saturday's solstice, the sun will begin its apparent journey southward, gradually shortening daylight hours until the autumnal equinox on September 22.

Huda Ata is an independent writer based in the UAE