UAE summer begins today: Emirates Astronomical Society

Dubai: Summer officially begins in the UAE today (June 21) from an astronomical perspective, marked by the summer solstice, according to the Emirates Astronomical Society. The solstice occurs at 08:25 GMT (12:25 UAE time), signalling the start of a three-month period that will last until the autumnal equinox in late September. Longest days of the year Ibrahim Al Jarwan, Chairman of the Emirates Astronomical Society, said the summer solstice represents the point when the sun reaches its northernmost position, directly overhead at the Tropic of Cancer. He explained that this results in the shortest midday shadow across the northern hemisphere, with some areas experiencing almost no shadow at noon due to direct solar alignment. The UAE will experience its longest daylight period between June 18 and 24, with around 13 hours and 50 minutes of daylight. Rising temperatures expected Temperatures are expected to increase significantly during the early part of summer, with daytime averages ranging between 41°C and 43°C, while night temperatures may reach 27°C to 31°C. The first phase of summer, from June 21 to August 10, will be characterised by generally dry conditions and increased wind activity. Seasonal winds and heatwaves During this period, 'Al-Barah' winds — typically from the north and northwest — are expected to intensify, often stirring sand and dust across parts of the country. Al Jarwan noted that hot air waves may also develop, raising temperatures by at least 3°C above normal levels for consecutive days, and sometimes lasting up to six days or more. In some areas, temperatures may exceed 50°C, accompanied by hot and dry 'Al-Samoom' winds. Humidity and storms later in summer The second half of summer, from August 11 until September 23, will bring a different pattern, with high humidity levels and continued heat. This period will see increased activity of humid 'Kous' winds, which can lead to the formation of cumulonimbus clouds, particularly over the Hajar Mountains, sometimes resulting in thunderstorms. Astronomical vs meteorological summer While astronomical summer begins with the solstice, meteorological summer in the northern hemisphere — based on average temperatures — runs from June 1 to August 31 each year. Experts said the changing seasonal conditions highlight the UAE’s diverse climate patterns, combining extreme heat, shifting winds and occasional storm activity across different phases of the summer season.