The north of the Zambezi basin has mean
annual rainfall of 1100 to 1400 mm which declines towards the south,
reaching about half that figure in the south-west. The rain falls in a
4-to-6-month summer rainy season when the Inter-Tropical Convergence Zone moves
over the basin from the north between October and March. Evaporation rates are
high (1600 mm-2300 mm) and much water is lost this way in swamps and
floodplains, especially in the south-west of the basin
