Lagos Weather & Live Flood & Harmattan Dust Map

Lagos is one of the largest and fastest-growing cities in the world, a sprawling coastal megacity built around lagoons on the edge of the Atlantic. Its weather swings between two dramatic seasonal extremes: a long, heavy rainy season that turns flooding into a recurring crisis, and the Harmattan — the dry, dusty wind that sweeps down from the Sahara and fills the air with desert haze. Telling these seasons apart, and reading the hazard each brings, is exactly what the live map helps with.

A low city and a lot of rain

Lagos sits low and close to the sea, threaded with lagoons and creeks, with large areas barely above sea level. That geography makes it intensely vulnerable to flooding. During the rainy season — roughly April through October, peaking around mid-year — heavy, frequent downpours can overwhelm the city's drainage in a matter of hours. With so much of the metropolis sitting so low, the water has nowhere to drain quickly, and serious flooding can follow even routine heavy rain.

The coast adds another dimension. High tides and ocean water pushing inland can compound the rainfall flooding along low-lying shorelines, and the city's rapid growth and rising seas make the long-term flood picture a pressing concern. For a metropolis of this scale and density, managing floodwater is one of the defining challenges of the wet half of the year.

The Harmattan: dust from the desert

Then, around December, the weather flips entirely. The Harmattan arrives — a dry, dusty wind that blows southward from the Sahara across West Africa, usually lasting into February. It carries vast quantities of fine desert dust, filling the air with a hazy veil that dims the sun, cuts visibility and degrades air quality across the region. It also brings unusually dry air and cooler nights.

For Lagos, the Harmattan is the seasonal opposite of the floods: where the wet season is about too much water, the Harmattan is about dust and haze. It's part of the same family of phenomena as the great Saharan dust plumes that ride the winds across the wider region — desert dust, lifted and carried far from its source, changing the sky and the air far downwind.

Reading it on the live map

Lagos is a tale of two seasons, and the key layer flips between them:

• In the wet season, watch the rain. Turn on Radar to follow storms and downpours and judge where flood risk is building across the low-lying city.
• In the Harmattan, watch the dust. Add the Smoke & Dust (aerosol) and Air Quality layers to see desert dust drifting down from the north and how much it's fouling the air.
• Mind the coast. Low shorelines face the added threat of water pushing in from the sea, as the storm-surge guide explains.
• Connect the dust story. The Saharan-dust and dust-storm guides explain how desert dust gets lifted and carried across the region on the wind.

Radar tells you when the water is the threat; the dust and air-quality layers tell you when the Harmattan haze takes over. In a city that swings between flood and desert dust, reading the right layer for the season is how you know what the sky is about to bring.