How Nigeria’s flood warnings work, and how to read the next alert

Updated 18:23 WAT, 30 Sep 2026: NIHSA has issued a new flood advisory covering 17 states from 28 September to 4 October, with eight at high risk.

Last week the flood warnings came thick and fast. The Nigeria Hydrological Services Agency (NIHSA) issued an alert, coded NFA-2026-262, placing parts of 15 states at high risk of flooding between 19 and 25 September. The National Emergency Management Agency (NEMA) responded by putting its emergency teams on red alert.

The states named were Imo, Cross River, Ebonyi, Benue, Anambra, Akwa Ibom, Lagos, Rivers, Edo, Kogi, Taraba, Delta, Bayelsa, Enugu and Abia. In Cross River alone, NIHSA listed 2,471 communities, 703 schools and 344 health facilities in at-risk areas.

A newer alert is now in force. NIHSA’s latest advisory, covering 28 September to 4 October, names 17 states, The Sun and The Whistler reported. Eight are rated high risk: Imo, Cross River, Ebonyi, Benue, Anambra, Kogi, Rivers and Enugu, according to The Whistler, which said about 6,800 communities, more than 5,800 schools and more than 2,000 health facilities lie in at-risk areas. Edo, Delta, Osun, Ondo, Ogun and Lagos are among the states rated medium to low risk.

To understand the warnings, it helps to know that hydrologists broadly separate flash floods, when intense rain overwhelms drains and streets within hours, from river (riverine) floods, when rivers rise and spill over their banks. River floods can arrive days after the rain that caused them, because water from a wide catchment, sometimes hundreds of kilometres upstream, takes time to travel down the channel. That delay is what makes forecasting possible.

How the forecasts are made

The long-range view is NIHSA’s Annual Flood Outlook. The 2026 edition, released in April, placed 14,118 communities in 266 local government areas across 33 states and the FCT in high-risk zones. NIHSA says this year’s modelling was upgraded to a hybrid system that integrates artificial intelligence, alongside a flood dashboard for decision-makers.

During the rainy season the focus shifts to short windows, such as last week’s seven-day alert. Gauging stations record river levels, and forecasters combine those readings with rainfall forecasts and models to predict where water will rise next. Last week’s alert flagged stations including Obubra, Itigidi and Epento in Cross River State for close monitoring.

How to use an alert

• Check whether your state, local government and community are listed, and note the dates covered.
• If you live near a river or on low ground, act early. NIHSA advises moving “people, livestock and valuables to safer, higher ground” where necessary.
• Never walk or drive through floodwater, across submerged bridges or into fast-moving water.
• Clear blocked drains around your home and store safe drinking water.
• Follow NIHSA, NEMA and your state emergency management agency for updates.

What next: The current advisory runs until Sunday, 4 October. Check whether your state and community are listed, and look out for fresh advisories from NIHSA and NEMA as the rainy season continues.