Why September humidity is triggering foggy mornings in Dubai, Abu Dhabi

Summer temperatures remain high across the UAE, but weather conditions are gradually shifting as September begins, bringing an increased chance of early-morning fog and mist.

The UAE's National Centre of Meteorology (NCM) issued a fog alert for September 2, 2026, from 1am to 8:30am, warning of reduced horizontal visibility in some coastal and inland areas.

High Humidity Raises Fog Risk

According to the NCM, relative humidity is expected to reach around 90 per cent overnight in coastal and inland areas.

The weather forecast for Wednesday, September 2, calls for fair to partly cloudy conditions, with convective clouds possible over eastern areas during the afternoon. Despite the gradual easing of temperatures, daytime highs are still expected to reach the low to mid-40s Celsius in inland areas.

The combination of hot daytime temperatures and increasingly humid nights is creating favourable conditions for fog formation.

How Fog Forms in the UAE

Fog may appear unusual in the UAE's desert climate, but the process is well understood.

During the evening, warm and moisture-laden air from the Arabian Gulf and Arabian Sea moves across the country. After sunset, the ground loses heat rapidly, cooling the air close to the surface.

When the air reaches saturation, water vapour condenses into tiny droplets that remain suspended near the ground, creating fog.

This type of radiation fog accounts for around 95 per cent of fog recorded in the UAE.

Light Winds and Dust Help Fog Develop

Wind speed also plays an important role in fog formation.

Research based on data from Abu Dhabi International Airport suggests that a light breeze of around five knots can help fog develop and settle. Stronger winds, however, can disperse the moisture and prevent dense fog from forming.

Dust particles in the atmosphere also contribute to the process. Fine sand and dust act as condensation nuclei, providing surfaces on which water vapour can condense into droplets.

Suhail Season Signals Seasonal Change

Emirati astronomer Ibrahim Al Jarwan, Chairman of the Emirates Astronomy Society, has linked the current weather pattern to the normal seasonal transition.

August and September typically bring higher humidity as the peak summer period begins to decline.

The UAE entered the traditional Suhail season on August 24, associated with the appearance of the star Canopus before dawn. Across the Arabian Peninsula, the season has traditionally been linked to the gradual retreat of summer heat.

The transition is gradual. Temperatures remain high, but humidity becomes more noticeable, while morning fog and dew become increasingly common in the weeks ahead.

Why Humidity Is Key to Fog Formation

Relative humidity is one of the most important indicators used by the NCM when issuing fog forecasts.

The key factor is the relationship between air temperature and dew point — the temperature at which air becomes saturated with moisture.

When overnight temperatures fall to the dew point, water vapour begins condensing into tiny droplets. The smaller the difference between air temperature and dew point, the greater the likelihood of fog.

In early September, the Arabian Gulf remains warm after months of summer heat, resulting in continued evaporation and increased moisture in the lower atmosphere.

When humid air moves inland and the desert surface cools after sunset, temperatures can fall towards the dew point, creating conditions favourable for fog.

Areas Most Likely to See Fog

Fog does not form equally across the UAE. Certain areas are more prone to it because of their geography and overnight cooling patterns.

Researchers at Khalifa University's Environmental and Geophysical Sciences Lab have identified the Sweihan desert and areas southwest of Abu Dhabi as major fog formation zones.

Historical NCM observations have recorded fog across several locations, including:

Sweihan and Al Ain
Al Fayah
Madinat Zayed
Ghayathi
Liwa
Abu Dhabi-Al Ain Road
Al Ain-Dubai Road
Al Maktoum International Airport
Ghantoot
Jebel Ali
Al Minhad
Saih Al Salam
Mleiha Road
Sheikh Mohammed bin Zayed Road
Emirates Road
The Al Dhafra region is also frequently included in NCM fog alerts, particularly across its coastal and western areas.

Desert Roads Face Higher Visibility Risks

For motorists, open desert routes connecting Abu Dhabi, Al Ain and Dubai are among the areas where visibility can deteriorate quickly.

Low-lying inter-emirate highways and roads across Al Dhafra can also experience dense fog, while parts of Dubai and Sharjah may occasionally be affected.

Drivers travelling during the early morning hours should therefore remain alert, particularly before sunrise when fog can be at its thickest.

What to Expect During September

Weather patterns in late August and early September have generally featured hot and mostly fair days, with convective clouds developing over eastern and southern areas during the afternoon and an occasional chance of rain.

At night, humidity is expected to rise, increasing the possibility of fog or mist before sunrise.

Although temperatures are expected to gradually decline as September progresses, the combination of cooler nights and lingering moisture could actually create more favourable conditions for fog.

Drivers Advised to Check Forecasts

Motorists who regularly travel on the Abu Dhabi-Dubai and Abu Dhabi-Al Ain routes are advised to check the NCM forecast before setting out early in the morning.

Drivers should also allow additional travel time and exercise caution whenever visibility is reduced, particularly on highways and desert roads during the hours before 9am.