 The season was an event of the annual cycle of tropical cyclone and subtropical cyclone formation in the South-West Indian Ocean basin.It officially began on November 15, 2018, and ended on April 30, 2019, with the exception for Mauritius and the Seychelles, which it ended on May 15, 2019.These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator.