Five weather systems set to drive UAE summer heat, humidity and dust

Dubai: The UAE is set to enter the hottest phase of the year, with summer weather shaped by five major air masses that influence temperatures, humidity and wind patterns across the country, according to a leading Emirati astronomer.

Ibrahim Al Jarwan, Chairman of the Board of Directors of the Emirates Astronomical Society and member of the Arab Union for Astronomy and Space Sciences, said summer in the UAE and across the Arabian Peninsula extends from the beginning of June until the end of August and is characterised by intense heat driven by a combination of regional weather systems.

According to Al Khaleej newspaper, Al Jarwan said the Indian summer low-pressure system remains the most influential weather feature affecting the region during the season. Formed over the Indian subcontinent, the system extends towards the Arabian Gulf when it intensifies, generating hot and dry conditions at times, or highly humid weather when combined with moisture from the Arabian Sea and the Gulf.

He added that the system is the primary driver behind the extreme temperatures typically recorded during the height of summer.

Another key influence comes from the subtropical high-pressure belt, which extends across latitudes between 20 and 35 degrees north and south. This system stabilises the atmosphere, suppresses cloud formation and rainfall, and contributes to prolonged periods of hot weather.

Al Jarwan also highlighted the role of tropical maritime air masses originating from the Arabian Sea and the Arabian Gulf. These reach their peak influence between late July and August, bringing hot and humid conditions that significantly increase humidity levels along coastal areas and raise the perceived temperature.

In contrast, tropical continental air masses form over desert regions and plateaus across the Arabian Peninsula, southwestern Iran and parts of Pakistan. These hot and dry air masses are most prominent during July, when they generate intense heatwaves, known locally as the peak of summer, accompanied by dry winds and occasional dust storms.

Trade winds over the Arabian Sea also play a seasonal role. When strengthened by the Indian monsoon system during July and August, they can transport large amounts of moisture towards the UAE, particularly the eastern coast. This often results in uncomfortable humidity levels, even overnight, and contributes to the formation of convective thunderclouds over the Hajar Mountains, a phenomenon locally known as the "summer clouds".

These conditions can also produce low cloud cover and drizzle along parts of the eastern coastline, while fog may develop overnight and during the early morning hours in inland areas, particularly in August and September.

Al Jarwan said June contains the longest day of the year in the UAE, with daylight hours exceeding 13 hours and 40 minutes around the summer solstice on June 21, when the sun appears directly above the Tropic of Cancer. Daylight hours then begin to gradually shorten through the remainder of the season.

Temperatures typically rise steadily throughout June before reaching their annual peak in July and August. Average daytime temperatures in June range between 39°C and 42°C, while overnight lows range from 27°C to 31°C. In July, daytime temperatures generally range between 41°C and 43°C, with overnight temperatures between 30°C and 33°C.

Humidity levels also increase noticeably during the second half of summer, especially in coastal cities. Al Jarwan said humidity can make temperatures feel significantly higher than actual readings, creating particularly uncomfortable conditions when combined with intense heat.

Average maximum humidity levels range between 75 and 90 per cent in June and between 80 and 90 per cent in July, while minimum humidity levels generally range from 35 to 45 per cent in June and 40 to 50 per cent in July.