A significant surge of Saharan Dust is forecast to move in across the Lesser Antilles on Wednesday night through Thursday, with Tropical Wave 15 leading the dust surge. However, higher concentrations of dust are forecast to affect northern islands, particularly the Leeward Islands.
What you need to know
— Saharan Dust Surges: Through Wednesday night, a mild to moderate dust surge is moving across T&T. A significant surge of Saharan Dust will move across the Lesser Antilles from early Thursday (July 10th) with high to significant concentrations of dust across the northern half of the island chain, and moderate to high concentrations across the southern Windward Islands, including T&T, through Monday, July 14th. The next surge (moderate to high concentrations) is forecast for July 17th.
— What Should You Do: Unusually sensitive groups are advised to take necessary precautions, particularly between Thursday and Sunday, while the general public remains mostly unaffected over the next seven to 10 days.
Current AQI Levels Across T&T
As of midnight (12:00 AM), Tuesday, July 8th, 2025, the official air quality monitoring stations from the Environmental Management Agency (EMA) at Beetham outside of Port of Spain, and San Fernando report air quality that are at good levels while all other stations (Speyside, Arima, Point Lisas) are not currently transmitting PM2.5 or PM10 data.
Unofficial air quality monitoring stations at Longdenville and Woodbrook report air quality levels that are good.
These measurements are based on PM2.5 (particulates smaller than 2.5 micrometers in size, typically associated with increases in Saharan Dust, vehicle exhaust, and smoke) and PM10 particulates.
Outside of rainfall, visibility, used as a proxy for Saharan Dust concentrations, at the A.N.R. Robinson International Airport at Crown Point, Tobago, and Piarco, remains at 10 kilometers over the last 24 hours.
Saharan Dust Forecast For T&T
July 7th through late July 9th: Mild to moderate concentrations of Saharan Dust with air quality levels generally at good levels, at times dipping to moderate. Horizontal visibility is generally unaffected.
Late July 9th through July 14th: Moderate to high concentrations of Saharan Dust, with peak concentrations likely on Thursday (10th), Saturday (12th), and Sunday (13th), with air quality generally between levels that are moderate to unhealthy for sensitive groups. Horizontal visibility is likely to dip between 5 and 8 kilometers on days with peak concentrations.
July 15th through July 16th: Mild concentrations of Saharan Dust with air quality generally at good levels, occasionally at moderate levels. Horizontal visibility is likely to remain at or above 10 kilometers.
July 17th: Moderate to high concentrations of Saharan Dust with air quality at moderate levels. Horizontal visibility between 8 and 10 kilometers.
What does this mean for you?
Generally, over the next 10 days, air quality levels are forecast to be mainly moderate, with periods of good air quality during the passage of the ITCZ or tropical waves. Between July 10th and 14th, air quality could dip to levels considered unhealthy for sensitive groups due to the high levels of dust mainly north of Trinidad and Tobago.
We’re now in a period where the Intertropical Convergence Zone, tropical waves, and occasional tropical cyclones may shield Trinidad and Tobago from the Saharan Dust events. While tropical waves are notable in moving dust across the Atlantic and the Eastern Caribbean, these periodic tropical waves also improve air quality.
Peak dust concentrations climatologically occur during June across the Main Development Region of the Atlantic, just east of Trinidad and Tobago.
The concentration of the dust that follows the wave depends on its strength as it moves off the West African Coast. This is because of stronger thunderstorms across Central Africa. As strong winds move downward and outward from these thunderstorms, they kick up dust as they move across parts of the Saharan Desert and transport it into the upper atmosphere. This “plume” of dust follows the axis of the wave as it progresses westward into the Atlantic.
Dust that enters the upper levels of the atmosphere can then be transported across the Atlantic Ocean. The plumes of dust eventually affect the Eastern Caribbean.
Larger, more concentrated plumes of Saharan dust begin in April and continue through November.
