Monthly average rainfall and wind vectors over Equatorial South Asia
The mean annual cycle of rainfall in Maldives shows a dry season from February to March and a wet season from April to November with the Southern most island garnering high rainfall during the December-January period when the Inter-Tropical-Convergence-Zone is located over Southern Maldives. The Maldives receives annual average rainfall that ranges from 1700 mm to the Northern most Hanimadhoo station to 2350 mm in the southern most Gan station. The character of the annual rainfall shows the drier months at February and March. The Northern stations receive highest rainfall during the summer monsoon month of June and the Southern most stations show a peak in December.
The Maldives undergoes seasonal reversal in wind directions with North-Easterlies prevailing from December to March and South-Westerlies prevailing from April to November on average. In the Northern most islands the South-Westerlies last from May to October. The wind speeds peak in the Northern region is in June and in the Southern most islands is in December.
There is gradual change in the climatic character of Maldives from North to South due to geography. Given that there are four stations that are distributed approximately evenly from North to South, following the Maldivian Department of Meteorology, we take Hanimadhoo as representative of the Northern atolls, Hulhule as representative of the Central atolls and Gan as representative of the Southern atolls. Kadhdhoo is located in the southernmost islands in the Central region in between Gan and Hulhule.
The Department of Meteorology demarcated seasons as the North-East monsoon (December to March) and South-West monsoon (April to November) – there is variation from North to South of the duration of the seasons. and seasons with strong ENSO influences. There are peaks in rainfall for most of Maldives in April to June and October to December – the ENSO influences are consistent as well in these seasons.