May marks the beginning of the season in most countries in West Africa. Over the course of the month, the seasonal rains progressed northwards from Central Africa and coastal areas of West Africa towards the Sahel region.
Most of the region was characterised by below average and erratic rainfall during this period. Particularly the western parts (Senegal, Guinea-Bissau, western Mali and northern Guinea) and most of the eastern parts of the region (northern Nigeria, southern Chad and Cameroon) experienced below average rainfall. These drier than normal conditions are confirmed by the Standard Precipitation Index (SPI). Some coastal areas (Liberia, Sierra Leone, southern Côte d’Ivoire, southern Ghana and Togo), as well as some central parts of the region (central Burkina Faso) experienced average to above average rains in May.
Vegetation conditions are below average across most of the southern parts of the Sahel, from southern Senegal across Burkina Faso, northern Ghana and northern Nigeria (particularly over the country’s Central Belt). These below normal vegetation conditions can be linked to a later than normal start of the 2022 rainy season, as well as the remnants of a difficult season in 2021, which ended early in some areas. Water resources are at very low levels across most of the Sahel.
The short-term forecasts indicate that by mid-June (20 June 2022), rainfall improvement will likely be observed across West Africa Region, in particular over the Sahel with widespread wetter conditions. This may alleviate the impacts of the early season dryness and lead to more favourable conditions for the start of the growing season.
According to the 2022 PRESASS seasonal forecast, average to above average seasonal rainfall is expected in most of the Sahelian Belt (from Senegal through to Chad), including Cabo Verde. Average to below average rainfall is expected in south-eastern Nigeria and south-western Cameroon. The seasonal forecast also suggests that the start of the season will be early to normal, with shorter than normal dry spells during the first half of the rainy season across the Sahelo-Sudanian zone.