Shadows will all but vanish at noon across the UAE this Sunday, when the sun climbs to its highest point of the year and ushers in the astronomical summer season.
The moment marks the summer solstice, the day the Northern Hemisphere tilts most directly toward the sun and receives its widest spread of daylight. For the Emirates, that translates into close to 14 hours of sunlight on June 21 — the longest single day on the calendar before the hours of light begin their slow retreat toward the autumn equinox in September.
The reason lies in the planet’s tilt of roughly 23.5 degrees, which on this date angles the northern half of the globe toward the sun at its sharpest. The Southern Hemisphere, by contrast, sinks into its shortest day and the opening of astronomical winter.
In a Gulf News report, Ibrahim Al Jarwan, chairman of the Emirates Astronomical Society and a member of the Arab Union for Astronomy and Space Sciences, said the brightest stretch of the year falls between June 18 and 24, when daylight in the UAE runs beyond 13 hours and 40 minutes. With the sun positioned directly above the Tropic of Cancer, he noted that noon shadows disappear in areas lying along its path, and across the wider Arabian Peninsula midday shadows shrink to their smallest of the year.
Longest day, however, does not mean hottest. Heat continues to build for weeks afterward as land and sea hold onto the energy they absorb through the season. Al Jarwan pointed to an old Arab observation of this lag, citing the saying, “There is no true heat until after the turning” — a reference to the weeks after the sun begins drifting south again. In the Gulf, the fiercest heat has historically settled over July and the early part of August.
From June 21 to around August 10, daytime temperatures in the Emirates are expected to sit between 41°C and 43°C, with overnight lows holding near 27°C to 31°C. The northerly and north-westerly “Barah” winds typically sweep through during this stretch, kicking up dust and reshaping the dunes. Heatwaves can push readings at least three degrees above the seasonal norm for days at a time, and in some locations the mercury climbs past 50°C during extended hot spells. Dry desert winds known as the “Samoom” occasionally add to the strain.
The character of summer shifts in its second half. From roughly August 11 until the autumnal equinox on September 23, humidity climbs while the heat lingers, and the moist south-easterly “Kous” winds grow more active. That added moisture can feed convective cloud over the Hajar mountains and nearby areas, occasionally spilling into localised thunderstorms and rain — a recurring signature of late summer in the country’s east.
Meteorologists draw the season’s boundaries differently from astronomers. Rather than tracking the solstice, they fix meteorological summer to the calendar, counting it from June 1 through August 31 each year.
