As Nigeria braces for the 2025 rainy season, the Nigerian Meteorological Agency (NiMET) has issued a cautionary advisory about the increased risk of cholera outbreaks and other waterborne diseases, particularly in areas expected to experience heavy downpours and flooding.
In its recently published 2025 Seasonal Climate Prediction, NiMET pinpointed several states, including Lagos, the Federal Capital Territory, Abia, Ebonyi, Cross River, Kaduna, and Akwa Ibom, as high-risk zones. The agency linked the health risks to poor sanitation in flood-prone communities, where water contamination could trigger widespread disease.
“Rising rainfall, storm surges, and warmer coastal waters are likely to contribute to excessive flooding, which in turn heightens the risk of outbreaks like cholera,” the report noted. The danger is particularly acute in communities still practicing open defecation, where fecal matter could seep into water supplies during flood events.
Beyond cholera, the climate forecast also raised red flags about potential surges in malaria, meningitis, and heat-related illnesses such as dehydration, heatstroke, and respiratory challenges. NiMET warned that even regions expecting near-normal rainfall could face flash floods due to intense, short-duration rainfalls that overwhelm drainage systems.
“Contaminated water sources will likely lead to increased cases of diarrhea, dysentery, and other gastrointestinal infections,” the agency added. Prolonged dampness is also expected to worsen respiratory infections due to mold and fungal proliferation.
The 2025 outlook shows coastal states like Lagos, Rivers, Delta, Bayelsa, Akwa Ibom, and Cross River could experience up to 290 rainy days—almost 80% of the year. The next tier includes states such as Ogun, Oyo, Ekiti, Osun, Ebonyi, Anambra, and Enugu, with projections ranging between 200 and 250 days of rainfall.
In central Nigeria, states including Kwara, Niger, Benue, Nasarawa, Plateau, Kogi, and the FCT are forecast to receive between 150 and 200 rainy days. Meanwhile, northern states such as Sokoto, Borno, Kano, Katsina, Jigawa, Yobe, and Zamfara are predicted to experience a shorter wet season, with 110 to 150 rainy days expected.
Overall rainfall will vary significantly, from as low as 405 mm in the northernmost regions to as high as 3,010 mm in the southern coastal belt, the report revealed.
Though average rainfall will remain close to long-term norms across most regions, states like Lagos, FCT, Abia, Akwa Ibom, Cross River, Ebonyi, and Kaduna are projected to record above-average precipitation.
NiMET also outlined the expected timeline for the onset and cessation of rains. Southern states including Lagos, Ogun, Ondo, Edo, Enugu, Ebonyi, Abia, Anambra, and Imo will see the earliest rains between March and April. Central areas are set to begin receiving rain from April to May, while northern states will likely experience their first showers between June and July.
The season is expected to taper off between October and December, beginning in the north and gradually retreating southward by mid-December.
A few regions, however, may face prolonged dry spells even during the peak of the rainy season. NiMET forecast severe 15-day dry periods in areas of Oyo such as Saki, Ogbomosho, Iseyin, and Ori Ire, while up to 21 days of dryness are possible in parts of the North between June and August.
In the South, states including Abia, Cross River, Delta, Bayelsa, and Akwa Ibom may experience moderate dry spells of up to two weeks.
Given the implications of this year’s climate forecast, NiMET urged local governments, health authorities, and emergency response agencies to prioritize flood preparedness, sanitation infrastructure, and public health awareness campaigns to mitigate potential disease outbreaks and displacement.
