UAE summer to end on Wednesday, bringing cooler air and chance of rain

Autumn will begin this week in the UAE, with the September equinox occurring on Wednesday. This astronomical event marks the sun crossing the equator, resulting in nearly equal day and night lengths. Ibrahim Ghonaimat from the International Astronomical Centre explained that the autumn equinox signifies the start of autumn in the northern hemisphere and spring in the southern hemisphere.

Even though temperatures do not change abruptly at the equinox, the UAE typically experiences more comfortable weather around mid-October, especially at night and in the early morning. In September, the gradual shift towards cooler weather begins as daylight hours shorten. While nights gradually cool, high humidity may keep conditions warm and uncomfortable, potentially extending into November.

The Suhail star's appearance in UAE skies on August 24 signaled the end of high summer. However, since its sighting, the National Centre of Meteorology has recorded temperatures consistently above 45°C, accompanied by foggy and humid mornings. The cause of the September humidity can be attributed to the sea remaining warm from the extended summer, leading to significant water evaporation.

Seasonal winds further contribute to the high humidity by bringing additional moisture from neighboring seas. Nights begin to cool slightly, allowing humidity to accumulate near the ground, resulting in the sticky, uncomfortable conditions and early morning fog commonly observed in Abu Dhabi, Dubai, and other coastal areas during September.

Rainfall during the autumn months is not directly caused by the autumn equinox. Instead, it depends on various atmospheric and climatic factors. According to Ghonaimat, rainfall events in the UAE usually occur between November and April. Winter clouds are expected to arrive in mid-October, with the likelihood of rain increasing as autumn progresses.

Ibrahim Al Jarwan, chairman of the Emirates Astronomical Society's board of directors, stated that a strong El Nino is anticipated to persist through February. This El Nino event is expected to bring average temperatures and an increased probability of rain across the UAE, extending into April 2027. Initially, during the beginning of autumn, the average high temperature will be 39°C, dropping to 26°C at night.

By mid-autumn, around early November, temperatures will rise to 31°C during the day and 18°C at night. By the season's end, around December 22, when the winter solstice occurs, highs will decrease to 25°C and lows will fall to 13°C.