• As the core period of the rainy season comes to an end during the month of September, West Africa remains characterised by below average rainfall. Rainfall deficits persist over most of the Sahel, in northern Senegal, most of Mauritania, central Mali, eastern Burkina Faso, western and northern Niger and southern Chad. Only coastal areas in the Gulf of Guinea and the Mano River countries benefited from more favourable conditions. From mid July to late August, the rainy season has been characterised by above normal rainfall, which offset early season dryness in most of West Africa, particularly in the Sahel. However, in September, unfavourable rainfall conditions were recorded, with a poor distribution of rainfall and below-average rains in most of the region – above all the Sahelian belt. In these areas, the erratic rainfall distribution during the critical period of the season could negatively impact crops and pasture conditions while heavy rainfall of above 200 mm in August and September resulted in flooding, that have affected large areas in Senegal, western central Nigeria, southwestern Mali, the western half of Guinea, southern Chad, and western Sierra Leone raising flooding concerns.
• Overall, the 2021 rainy season (between 1 May and 30 September), has been characterised by mostly average to above average conditions in West Africa. Rainfall deficits mainly affected northern Mauritania, central and northern Mali and northern Niger.. It is important to note however that these normal to above normal cumulative rainfall amounts hide the poor temporal distribution of the rains over the season, particularly over Sahelian countries, where most of the rains were received between July and August (see previous issues of this bulletin). Beginning from mid-July to late August, the rainfall situation over the region has improved resulting in a significant decline in cumulative rainfall deficits. During September rainfall decreased resulting in a poor distribution of rainfall, which has led to below average condition. These developments, cumulated to the erratic rainfall distribution over the course of the season, is expected to result in a negative impact on crops and pasture development – particularly in areas where early season dryness has persisted for a very long time, such as in northern Senegal, southern Mauritania, central and northern Mali, northern Nigeria, and northern Niger and Lac Chad. In central Mali and southwestern Niger, rainfall deficits in July were compounded by a severe deficit in September, which is likely to impact crops at critical flowering and maturation stages and exacerbate poor conditions resulting from ongoing conflict. There is concern in localized parts of southern Chad impacted by ongoing flooding.
• As a result of the mostly average to above average rainfall in the region since mid- July, markedly above average vegetation cover extends over much of the Sahel. Meanwhile a low vegetation recovery can be observed in some pockets in the western parts of the region (southern Mauritania, northern Senegal, central Mali), in northern Nigeria and around Lake Chad, due to early rainfall deficits and erratic seasonal rains. In these areas affected by poor vegetation conditions, the pastoral lean season might start earlier than usual this season • According to short-term forecasts covering the period until 10 October 2021, Rainfall will be below average in most of the region from Senegal to northern Nigeria extending into Chad. This indicates an earlier than normal end of the 2021 rainy season. Only northern Senegal, Mauritania, central and western Mali and pockets of south-western Mali will likely experience above average rains, with little expected impact on crop conditions..