UAE weather: it's officially autumn equinox today, so why still 45°C?

Dubai: If it doesn't quite feel like autumn outside your window this morning, you're not imagining things. The UAE technically crossed into the new season in the early hours of Wednesday, as the September equinox arrived at 00:06 GMT (4:06am UAE time), the moment the sun sits directly above the equator before continuing its shift south for the Northern Hemisphere's winter half of the year.

It's the point on the calendar when day and night come closest to equal length everywhere on Earth, and the official marker that the region has begun tilting away from the sun.

On paper, it's the biggest seasonal turning point of the year. On the ground, the National Centre of Meteorology's (NCM) latest bulletin shows the UAE is in no hurry to feel it. Internal areas of the country are forecast to hit highs of 43°C to 45°C today, coastal and island regions between 37°C and 42°C, and even the country's cooler mountain belt sitting at 29°C to 35°C, readings that put this equinox noticeably warmer than the one marked a year earlier, when coastal highs were closer to the mid-30s.

How the heat breaks down by emirate

Dubai, Sharjah, Ajman, Umm Al Quwain and the city of Abu Dhabi fall under the NCM's "coastal and islands" band, with today's highs expected between 37°C and 42°C, easing to lows of 27°C to 33°C overnight. Ras Al Khaimah and Fujairah track a similar coastal range, though the high ground around Jebel Jais and the wider Hajar chain stays noticeably milder, with highs of 29°C to 35°C and lows dipping to 25°C, the coolest air in the country today.

It's further inland, in Al Ain and the interior stretches of Abu Dhabi emirate such as Liwa and Al Dhafra, where the mercury climbs hardest, with highs reaching 43°C to 45°C and lows only easing to 21°C to 27°C by early morning.

Humidity, wind and sea conditions

Skies are expected to stay fair to partly cloudy, with a chance of convective cloud building eastward and southward through the afternoon. The NCM bulletin doesn't call for organised rainfall today, though isolated activity can't be entirely ruled out where those convective clouds develop. The bigger story is humidity: relative humidity climbs sharply overnight across both coastal and internal areas, reaching 70 to 90 per cent, which raises the odds of mist forming over some western areas by Thursday morning.

Winds are light to moderate out of the southeast to northeast, generally 10 to 20 km/h but freshening at times to around 30 to 35 km/h, particularly inland and in the mountains. The sea stays slight in both the Arabian Gulf and the Gulf of Oman.

What the next few days look like

Rather than an immediate drop, the NCM's four-day outlook actually points to temperatures ticking up slightly on Thursday before settling into a fair, partly cloudy pattern through the weekend, with no significant rain chances flagged over the period. Winds are expected to swing from southeasterly to northwesterly by Thursday, then shift again toward the southwest by Saturday and back to the northeast by Sunday, a sign the atmosphere is beginning to reorganise itself for the new season, even if the thermometer hasn't caught up.

Humid nights and early mornings are forecast to persist through Sunday, spreading the chance of fog or mist from the west to coastal and internal areas more broadly as the week progresses, with the sea expected to remain slight throughout.

Autumn on the calendar, not yet in the air

The equinox is an astronomical event, tied purely to Earth's position relative to the sun, and it doesn't reset the weather overnight. In the UAE, the real transition tends to show up gradually over the following weeks, as nights lengthen, humidity patterns shift, and the daytime highs of summer slowly give way to the milder, more comfortable stretch the country associates with October and November.

For now, residents can expect today to look and feel a lot like the summer they're leaving behind, with the more noticeable cooling still some weeks out, and an early morning mist or two in the meantime, as the season quietly turns.