weather term
Monsoon
A seasonal reversal of wind direction that brings a distinct wet season to large parts of Asia, West Africa and northern Australia.
Monsoons are driven by the difference in how quickly land and ocean heat up: as land warms faster than the sea in summer, it draws in moist ocean air that brings months of heavy rain, then reverses direction in winter as the land cools faster than the ocean. The exact onset date of the wet season varies from year to year and is one of the most closely watched forecasts in the countries it affects, since agriculture across the region depends on its timing.