Saharan dust and haze

Five-day Saharan dust outlook for the tri-island state.

Sample content — not an operational product

The dust outlook is not yet published from the GMS forecast system. The figures on this page are illustrative and must not be used for any weather, marine or safety decision.

Five-day outlook

Day	Concentration	Visibility	Guidance
Today	Light	Good — over 10 km	No action needed
Tomorrow	Moderate	Reduced — 7 to 10 km	Sensitive groups take care
Day 3	Moderate to heavy	Hazy — 4 to 7 km	Limit strenuous outdoor activity
Day 4	Heavy	Poor — under 4 km	Sensitive groups stay indoors where possible
Day 5	Moderate	Reduced — 7 to 10 km	Sensitive groups take care

Concentration levels

Level	What you notice	Who is affected
Light	Slight haze on the horizon	Nobody, generally
Moderate	Milky sky, hazy distance, muted sunset colours	Asthma and respiratory conditions
Heavy	Visibility clearly reduced, dust settling on surfaces	Respiratory and cardiovascular conditions, children, older adults
Very heavy	Marked haze, sun dimmed at midday	Everyone; sensitive groups significantly

Where the dust comes from

Between roughly May and September, strong winds lift mineral dust from the Sahara into the Saharan Air Layer — a dry, dusty mass of air that crosses the Atlantic in five to seven days and arrives over the Eastern Caribbean.

The same air layer that carries the dust is dry and stable, which suppresses shower activity and can weaken developing tropical systems. A heavy dust episode often brings quieter weather with it.

Health guidance during a dust episode is on the health and weather page.