Favorable rainfall conditions during the rainy season over the Sahel and a slow start of the short rainy season in the Gulf of Guinea countries.

• The Intertropical Front (ITF) reached its northernmost position and began its southward retreat, but it is still north of its climatological position (Figure 1).
• Globally, the region has experienced below-average to average cumulative rainfall, with some localized areas receiving above-average amounts (Figures 2&3).
• Heavy rainfall has triggered widespread flooding across West Africa, raising risks in several countries.

The Intertropical Front (ITF) reached its northernmost position during the second and third dekads of August and began moving southward in the first dekad of September over the eastern sector, followed by the western sector in mid-September. By the second dekad of September, the ITF had shifted southward along most of its length compared to its previous position. It was located slightly north of its climatological position across the entire region. Its dekadal average position ranged from 18.6°N over Mali and Mauritania to 16.5°N in eastern Chad (Figure 1).

Seasonal cumulative rainfall anomaly from April 1 to September 20, 2025 (Figure 2) has been below average to average over most of the Sahelian and Sudano-Guinean region. Some localized areas exhibit moderate to severe deficits, including eastern Mauritania, southern and western Mali, northwestern Niger in the Sahelian band; central-western Liberia, southwestern Côte d’Ivoire, central-eastern Ghana, central Togo, central Benin, central-western Nigeria, southern Cameroon, and southeastern and northern Central African Republic in the Sudano-Guinean and bimodal zones.

Figure 3 shows that across the Sahelian band, rainfall conditions generally remained favorable from August 16 to September 15, 2025, except in eastern Senegal and eastern Mauritania, as well as western and southern Mali, where severe rainfall deficits but no extended dry spells were observed. 

Additionally, localized areas in northwestern Niger experienced moderate to severe rainfall deficits and dry spells of less than 10 days. However, the combined estimated and forecasted rainfall from September 11 to October 05, 2025, indicates that significant relief is expected over the areas mentioned above (Figure 4). 

Since July, heavy rainfall has triggered flooding across several West African countries. Sierra Leone, Guinea-Bissau, western Guinea-Conakry, Senegal, The Gambia, and southwestern Mauritania have all been affected. In Nigeria, flooding has caused widespread damage in Bauchi, Plateau, and Niger states, while reports also indicate flooding along the country’s four major rivers (Niger, Benue, Sokoto and Komadugu rivers). Elevated rainfall in recent weeks has raised flood risks in southwestern Niger, northern Burkina Faso, and central Mali. Since July, sustained moderate to heavy rainfall has caused flooding along the Logone and Chari rivers in Chad, with the flooding also expanding into northern Cameroon. Flooding has also been observed in northeastern Ghana, as well as parts of northern Togo and Benin, and northern Niger. These conditions are not only displacing communities but also threatening standing crops, putting the current agricultural season at risk. According to the Advanced Disaster Analysis and Mapping, an estimated 371,911 hectares of cropland in Mali and 193,767 hectares in Chad are flooded. 

• According to NOAA Physical Sciences Laboratory forecasts, the second rainy season from September to November is expected to be below average to average over the Gulf of Guinea (Figure 5). Conversely, during the same period, rainfall is expected to be above average in southern and eastern Mali, Niger, Burkina Faso, central and northern Nigeria, Chad, northern Cameroon, the Central African Republic, and average in Senegal, The Gambia, Mauritania, and western Mali (Figure 5).
• According to the NMME-based streamflow  (September 2025–January 2026) and GloFAS streamflow (15 September–27 October 2025) forecasts, there is a high likelihood of localized flooding along the Senegal River in Senegal, upstream Niger River in Central Mali and Burkina Faso, along all four major rivers in Nigeria (Sokoto, Komadugu, Niger and Benue), and along the Logone river in Chad until the end of October.
• According to the FAO Locust Watch, there is still a possibility that new adult groups may appear in Mauritania, and they may also emerge in Mali, Niger, and Chad. Summer breeding will increase in Chad, Niger, Mali and Mauritania.