Causes of drought in Bangladesh are related to climate variability and non-availability of surface
water resources. The immediate cause of a rainfall shortage may be due to one or more factors
including absence of moisture in the atmosphere or large-scale downward movement of air
within the atmosphere which suppresses rainfall. Changes in such factors involve changes in
local, regional and global weather and climate. While it may be possible to indicate the
immediate cause of a drought in a particular location, it often is not possible to identify an
underlying cause.