As autumn enters MENA, why are some countries slower to cool?

The Middle East will see a gradual and uneven transition into autumn, with summer-like heat likely to linger longer across the Gulf than the Levant, weather experts have told The New Arab.

ArabiaWeather, a leading weather company in the Arab world, said the autumnal equinox does not trigger an immediate drop in temperatures, with geography and atmospheric conditions determining how quickly cooler weather reaches different parts of the region.

"For the Middle East, however, the transition into autumn is not immediate. The region is relatively far from the Arctic, so the seasonal change occurs gradually rather than as a direct or sudden response to the equinox itself," ArabiaWeather told The New Arab.

The assessment comes after the Middle East endured another period of extreme summer heat, with temperatures in parts of the region reaching 50°C.

But ArabiaWeather stressed that the intensity of this year's heat does not necessarily mean autumn conditions will arrive later than usual.

Instead, the shift will largely depend on the movement of air masses and changes in atmospheric pressure, with significant differences expected between the Levant and the Arabian Peninsula.

"The transition between summer and autumn is characterised by an interaction between different weather patterns. Remnants of summer conditions can persist while cooler autumn air masses begin moving toward Eastern Europe and the Mediterranean," ArabiaWeather said.

"This interaction can lead to noticeable fluctuations in temperatures, with warmer periods followed by cooler ones. Such temperature variability may continue through October, although its timing and intensity will vary from one part of the region to another."

Why will the Gulf stay hotter for longer?

ArabiaWeather said the seasonal transition generally moves from higher to lower latitudes, meaning the Levant is more likely to experience cooler conditions earlier than the Gulf.

"The Levant is geographically closer to the Mediterranean, Turkey, and Europe, making it more exposed to moderate and cooler air masses moving from Europe and the eastern Mediterranean," the company told The New Arab.

"By contrast, the Arabian Peninsula and the Gulf remain more influenced by the subtropical high-pressure system, or the Arabian high, associated with the heat dome that dominates the region during summer."

The system takes longer to weaken and retreat, ArabiaWeather said, making the transition towards autumn conditions generally slower across the Gulf and Arabian Peninsula than in the Levant.

That means countries in the Arabian Peninsula could continue experiencing summer-like conditions even as temperatures begin falling more noticeably further north.

The shift is unlikely to be linear, however, with ArabiaWeather forecasting periods of warmer and cooler weather as competing weather systems affect the region through October.

Does the extreme summer mean autumn will come later?

Despite temperatures across parts of the Middle East reaching 50°C during the summer heat, ArabiaWeather said there was no direct correlation between the intensity of summer temperatures and the timing of the seasonal transition.

"This transition is influenced more directly by large-scale atmospheric patterns, including the movement of air masses and changes in the distribution of atmospheric pressure," it told TNA.

The astronomical start of autumn in the Northern Hemisphere was marked by the autumnal equinox on Wednesday.

The equinox occurs when the Sun, in its apparent annual motion, crosses the celestial equator from north to south. Around this point, the Sun rises close to due east and sets close to due west.

"After the equinox, the Northern Hemisphere gradually enters a period of longer nights, and temperatures begin to decline more noticeably in those areas," ArabiaWeather said.

Astronomical autumn will last until the winter solstice on 21 December.

Could El Niño bring a wetter autumn?

ArabiaWeather also pointed to the potential influence of the El Niño climate phenomenon, which develops in the Pacific Ocean but can disrupt weather patterns around the world.

El Niño tends to raise global temperatures and alter rainfall patterns, potentially contributing to drought in some regions and heavier rainfall in others.

For parts of the Middle East and wider Arab region, however, ArabiaWeather said its effects could favour increased rainfall during the coming months.

"Statistically, its effects are expected to be favourable for rainfall amounts and precipitation opportunities across parts of the Arab region and the Middle East, particularly during autumn, supporting expectations of a more active autumn in terms of rainy weather systems," the company said.