The flow of the rivers and the flooding of the Inner Niger Delta is not determined by the rainfall of the last week(s), but by the accumulated, total rainfall in the wet season. Also this information is gathered, based on the daily estimates of rainfall as shown above. The maps below shows the total rainfall (mm) for the last 180 days in three ways:
Rainfall during the last 180 days: total amount (mm)
Rainfall during the last 180 days: absolute deviation (in mm above or below the long-term average).
Rainfall during the last 180 days: relative deviation (in per cent above or below the long-term average)